I'd mix the classic features of the Warlord with the rather bland fighter chassis, giving us a real master of combat, being the class to pick to be the best at fighting and making your group fight.
For starter I'd go with:
Put the support features of the Banneret and the improved help features of the Expert sidekick. (maybe to replace the bonus feats with actual features).
I do like this general idea.
My own take has been a monk-chassis class I call the Captain, that has a “Presence” aura that starts at 10ft and expands with levels, and gives a boost to Allie’s and debuff to enemies, depending on what presence you choose, and then you have manuvers you can do that usually involve your allies in some way.
Either you set someone up by using the help action as part of the attack action, or as a bonus action you can help multiple allies in your aura, or enemies have to save against frightened in your aura and your allies deal extra damage against frightened targets, etc
Or, you lead the strike, making an attack and then giving up the other to let an ally attack. (Requires level 5) or you could charge as an action, only making one attack but all allies within presence can move thier speed and gain a beefy damage buff to their next attack as a reaction.
You spend mettle to do this stuff, and your mettle die step increases with levels.
But a fighter chassis might could do all that with less fiddliness…