CM
Adventurer
The first question I would ask is: why do these things need to be CS abilities?
Why reinvent the wheel? CS seems to be a pretty elegant system open to lots of expansion. If you break every possible maneuver down to unique mechanics by class again then you get into one of the classic complaints about 4e--that every class has its own unique power list and there are 5 different versions of a maneuver that amounts to "damage plus trip" or "damage plus daze." I could see CS ending up with a list of abilities by level, with each ability available to all, a few, or even a single class, much like the 3rd edition spell lists (or indeed, the existing 5e spell lists).
If each class has its own resource system then you're back to paladins expending their divine focus to knockback enemies, barbarians invoking primal might, rangers spending their quarry dice, etc--a dozen different fiddly subsystems when one elegant system could suffice. In fact, I would include rogue's sneak attack in here, as well. Sneak attack could easily be rebuilt into a version of combat superiority that the rogue can only unleash with advantage. It could also let the rogue power all those sneaky rogue tumbling escape maneuvers if he needs to focus on defense rather than offense (for those times he doesn't have advantage). But that's a topic for another thread.
And the second question would be, if they do need to be CS abilities, why can't they be a combat style option for the fighter? And if they don't need to be CS abilities, what unique abilities might work better for the Warlord or Barbarian or Ranger class's schtick?
Why can't the Warlord have those features? Fighters get all those + CS maneuvers.
Why do you have to do that in order to hit the archetype of a combat commander? Can't you just have fighter who employs helpful CS maneuvers balanced with other CS maneuvers?
The 4e warlord makes a lot of concessions to the fighter in terms of armor and shield proficiencies, weapon proficiencies, hit points, and healing surges. The fighter is strictly better in all those categories. In return, the warlord gets to do some things the fighter cannot--namely, provide healing for allies through a variety of ranged and area effects.
Presumably, the 5e warlord will also make some concessions in terms of raw power in order to provide access to healing (or temp HP or whatever floats the wotc boat). Frequent healing (or even temp HP) is something that I don't think most people would see as appropriate for the fighter class (aside from something like Second Wind).
I think other classes should get other spellcasting methods, too. Sorcerers and Warlocks are beginning that process already, and I'd encourage them to go father. I've pointed out that I don't think either one should need "spells," either, and I'd be entirely happy with a Channel Divinity-based cleric, leaving Vancian magic to be a Wizard-based thing.
Well, wotc doesn't seem to be going in that direction. Warlocks get both spells and their own unique feature, invocations. Sorcerers get spells and sorcerous powers. Clerics get spells and channel divinity. They all gain them at different rates and at different levels, but they use the same general framework. I feel that CS and the martial classes should be the same.