It’s interesting that the fighter is barely behind the bard, here.
I can definitely see how it could be done, and I’d absolutely love to make some variant features for the fighter that gear it more toward support and leadership, perhaps even gaining followers again. I mean, noble/knight background can do it, why not a class feature?
Actually it would be super easy.
Replace the
Proficiencies block with slightly more limited armor and weapon set, and gain a skill and a tool.
Replace the Second Wind with a similar effect that you can use on an ally.
Replace the
Action Surge with the ability to grant an action to an ally. Limit as necessary. Alternatively, swap it with the ability to grant an attack when you make an attack, x/short rest.
Or even get weird, and swap in an ability to grant extra bonus actions and reactions.
Indomitable becomes an ability to boost an ally’s save, or a bonus to saves and ability checks with that you’re proficient in within 10ft of you. level 9 is high enough, if someone MCs to get this, good for them.
3rd and 4th extra attacks are replaced with group buffs when you take the attack or help action or use an action to cast a spell or use a special ability gained from your levels in this class.
Add
A couple leader-oriented fighting styles, and the UA variant ones
A BM maneuver where you make an attack that only deals your superiority die in damage on a hit, and grants an ally an attack without costing your BA.
More support Manuevers.
At level 5, gain the
Paragon of Martial Prowess feature. You gain 1 loyal follower, using stats specially designed for this. You gain an additional follower at level 9, 11, 13, 17, and 20. Most of your followers would be retainer types, and wouldn’t even adventure with you. Instead, they keep your home, which gives certain minor benefits to the whole party when the group spends 1 week or more resting and spending downtime there.
None of the follower stats make for someone you want to bring into danger often. They’re there for flavor, and to make adventuring life a little easy in subtle ways like carrying your gear and are more of an interaction and exploration benefit.