On the other hand pointing out that every existing class is a miserable failure at being a warlord and it would take radical surgery to the point of effectively being a new class on any of them isn't the same thing at all.
No. This is an approach destined for disappointment also, as it provides no specifics or feedback. It's a declaration only, a declaration that assumes this is fact, while making subjective claims. This is called Dogmatism or Appeal to False Authority.
Without specific examples it's an essentially meaningless statement.
I've already given two entirely different suggestions - the first being how to make them their own class, and the second being the sheer amount of radical surgery you would need for a fighter.
Can you link to these please? I really don't want to comb 170+ posts, or even other threads, to find the relevant portions. It would really help if you could point them out.
No. Just provide specifics. Criticism is a different skill to design.
Whatever works for you is just fine. For those who can or are willing to provide analysis and alternatives, it will be greatly appreciated.
No more than the fighter. Possibly less. This is largely irrelevant.
Is there a mechanical reason why this is irrelevant, or is this personal opinion?
I ask because another has specifically stated that less is desirable.
I know that the 4E Warlord had smaller Hit Dice than the Fighter, but I also know that survivability in 5E is less about To-Hit bonuses, than it is about HP (the two sides of the Bounded Accuracy coin).
Which do you prefer of these two options, D10 or D8...?
This question is putting the cart before the horse. Multiple attacks are simply one large at will DPR mechanic. On the other hand they are needed for damage to scale properly - all the classes without multiple attacks either have an escalating sneak attack or an escalating cantrip. On the gripping hand multiple attacks are the fastest form of damage scaling. If you scale a warlord's attacks the way a valorous bard's attacks scale this wouldn't be a problem.
Okay. I understand what you're saying. Question though: Would you prefer a scaled attack ala valorous bard, and lose the potential action economy resource of multiple actions (attacks), or would you like both?
What about instead of multiple attacks, you have multiple actions at the same accumulation rate as a Fighter, but they cannot be used for actual attacks - only for Warlord maneuvers?
Mu. Warlords with the right options should be capable of wearing the best armour. Warlords without shouldn't.
So, Feats rather than class abilities? Or should Tactical Warlord and Inspiring Warlord be subclasses (archetypes) of a Warlord class, with armor and weapon proficiencies stated there? If so, what should the default armor and weapon proficiencies be?
None and all. The only warlord power all warlords share is Inspiring Word.
That doesn't help very much. I think it's safe to say that it's unrealistic to port every Warlord power to 5E. It's simply too many options and goes against the more simplified system philosophy of 5E. Not to mention that some powers are just higher level versions of other powers - which could be addressed with scaling effects in 5E.
I've also read enough conversations about 4E to know that even 4E fans consider some powers absolutely crucial, while others are considered real stinkers.
I find it hard to believe that you can't identify some of the powers that would be absolutely crucial to include...
And again you are looking at the trees rather than the forest.
Better would be "What defines the warlord that the 5e fighter can't do"
The simple answer to that is "The fighter hits you with their axe. The warlord hits you with the Barbarian."
Now that's unnecessarily captious. Since mechanics define what a class can do, that means that you need mechanics to enable a Warlord to "Hit you with the Barbarian." Those mechanics - or at least some of those mechanics - the most common among all types of Warlords - are codified in both 4E and 5E as Class Features.
What class features should a Warlord class have?
What class features should a Warlord not have?
And that is where you start. You need to build a class that is skilled at hitting the monsters with the fighter, the barbarian, the rogue, and other PCs. They should be able to range from a Leonidas-style solid melee combatant, leading from the front and giving other people openings to a lazylord who never actually makes an attack roll.
As a general philosophical approach to the class, this sounds great.
Now on to specifics...