This is something I'm wrestling a bit both with the warlord idea and with the idea of a beastmaster ranger (who currently can give up their attacks to get other attacks from their beast). Weirdly, one segment is asking to give up actions to others; the other is asking to NOT HAVE TO give up actions to get others to do things.
Both are legitimate. One key difference is probably whether the target of the action-grant is a PC or NPC - another might be whether it's separate from the character, or a class feature.
In 5e, numbers and the action economy (though simplified) tell very heavily. Balancing that can be tricky. It probably can't be done perfectly at the design phase under the 5e paradigm, the DMs have to come into it where the dice meet the tabletop - and 5e empowers them to do so.
Can we do what the warlord could in 4e with what we have in 5e now? What the Warlord concept should be able to do when unconstrained by 4e formal Role? No to both, not even close. The warlord-like options in 5e are extremely limited, of questionable viability, and spread out among several classes and other options.
Of course -- the problem is that we already have, with the battlemaster fighter. Between Commander's Strike, Distracting Strike, Maneuvering Attack, and Rally, it's possible to make a 3rd level character that feels very much like a 4E warlord
A specific, very offense-focused Bravura Warlord, perhaps, and, only at 3rd level: as he levels up, he never gains another Warlord-appropriate maneuver or feature, because he's already got all of them that the sub-class offers. That's what I meant by "extremely limited." And, yes, it is a problem. A full Warlord class is the solution.
I also feel that a 4E style tactical warlord design would be bad for the game -- the principal effect of the 4E warlord, after all, was to basically surrender her own actions and give them to the most optimized ally in the party. I don't see that as a playstyle worth encouraging.
You're thinking of the oddball 'lazy' builds, they were a quirk that some fans siezed upon, but not the primary thrust of the class, to really fully-realize the grant-every-action concept, Shaman|Warlord hybrids worked better.
Most warlord exploits had the warlord attacking and applying a rider, reacting to an enemy action, or using a minor action to benefit an ally. Full action-grants were there, and they're appropriate, but they were a small part of the class.
As to encouraging playstyles, 5e was conceived in part as a response to strident complaints that there were certain playstyles that weren't being supported. Using the exclusion of a playstyle as a reason to tell everyone who might every play D&D that they can't ever play a warlord is doublely exclusionary, and diametrically opposed to the sentiments upon which 5e was based.
Next, I think the differentiation of all the different aspects of the 4E warlord is an admission by the 5E designers that all of those aspects should not be combined in a single character, or at least not easily. I won't go so far as to call it a 'toxic' design, but the idea of a highly-tactical, chessmasterish character goes against a lot of the 5E design ethic about streamlining and taking complexity out of combat.
I'm afraid I have to disagree very strongly with that assertion. Trying to play a character like that in 5e, now, with no way of modeling it bu badgering the other players into conceiving and executing complex battle plans, and trying to argue the DM into allowing them to succeed, would, indeed, be a nightmare - one that most players know better than to even try, even if they have the talents to possibly pull them off. Modeling such a character by putting those functions into class abilities that could simply be used by the player to benefit his fellow party members, would be a case of streamlining and removing complexity.
Finally, I'm not sure classes invented simply as prior edition system experiments are always germane to the current system, and even the concept of 'playing with the system' in that way is questionable. To the former point, the Favored Soul was a 3E class that asked the question 'what if we had a divine sorcerer?' I'm not sure we need a divine sorcerer in 5E, but players who want to play one might well disagree.
The Sorcerer was also originally just a 'system experiment' for Spontaneous Casting. The Warlock was conceived as an experiment in at-will casting. The spontaneous casting vs prepped casting distinction was gone in 4e and is still gone in 5e, but the Sorcerer is in both editions. Casters have had at-will attacks in both 4e and 5e, but the Warlock was still a class in both editions.
The Favoured Soul has already appeared in UA.
, as long as you're not a 4E purist, in which case, you should probably just still be playing 4E. (Nothing wrong with that, by the way; I'm both playing in and running 4E games to complete the LFR Epic campaign.)
Again, if that's what you want, you can homebrew it or stick with 4E; I don't think we need to spend official resources on something that isn't really germane to the design of the system.
Look, I run 5e. I promote 5e at conventions. I defend it from baseless attacks on-line. I am a D&D fan, going back to 1980, and have given every edition since then a fair chance. Telling me it's not my game and I shouldn't also have a chance to have some fun playing it is offensive.
We have a system where complex initiative, playing on a grid, and even customization via feats and multiclassing are all optional rules systems. I guess I don't really see the benefit in adding a bunch of classes, solely for the benefit of folks who remember them fondly from prior editions, solely as additional options.
So you don't see the point of the Warlock or Sorcerer, nor of the Totem Barbarian, Eldritch Knight, or Arcane Trickster? You're entitled to your opinion, but you seem a little quick to want to pair everything down to just the simplest version of the game. Maybe you should just play the Basic Game? Hey, at least I'm not suggesting you be expelled from D&D entirely for what you want. If that's going too far, you can still play the Standard Game and never be bothered by any Favored Souls, Mystics, or other, possible, optional classes that might come down the line, including the Warlord. Adding the Warlord won't in any way stop you from having the game you want to play. Blocking it from ever being in 5e will stop me from having the game I want, and have had in the past.
I do not accept assertions that 5e is structurally incapable of handling the Warlord. 5e has a looser design paradigm, and empowers the DM to handle balance & playability issues in the way that works best for their individual campaigns, that makes it much /more/ able to handle the addition of new classes, not less. To suggest that 4e could handle the Warlord and 5e can't is to call 5e the inferior system. That's not productive.
Probably, as long as you also point out that it's
not a stand-alone class in Fifth Edition, but a sub-class of the sorcerer.
Warlord as a sub-class of fighter is simply coming up with additional combat maneuvers for the battlemaster, possibly incorporating a level requirement to represent 'higher level' warlord abilities.
That's getting closer.
What you'll run up against, going that route, is that the Battlemaster is already a very potent sub-class in terms of DPR via multi-attacking. Anything else it does needs to ether stack/ride with that (which they currently do, CS dice adding DPR, and maneuvers tacking on other effects), or be competitive with it as an alternative action. You can't take either of those very far without breaking the sub-class. CS dice are already very limited and the Battlemaster can burn through them rapidly (and if he doesn't, is probably using sub-optimal tactics for many situations), support classes manage limited resources, but they do need some depth to those resources, to be called upon in times of need, and the Battlemaster can't provide that. There just isn't room in the design space left to a fighter sub-class to do justice to a Warlord class, even a limited vision of it defined only by what it could do in 4e, let alone the concept-based approach that 5e has taken with other classes.
Expanding maneuvers could be a way to go, though, just not within the battlemaster's limited design space (that'd be like trying to squeeze all caster classes in under the Eldritch Knight). A class-independent system of maneuvers could be used to enable more options for martial characters, including the ability to add classes and sub-classes more readily.