I, for seem reason, find captains incredibly fascinating. I think the dev team should make use of the assets of the captains and make them playable, although they might have an incredibly limited move set, their raw damage might make up for it.

Currently Most Captains have 63 health, with lights that deal 22 damage, and heavies that deal 35.

If ubisoft were to make them playable, they'd have to edit their stats, because currently, they have an insane dodge speed, mainly due to them using dodge to get out of player's way.

What I suggest stats that make them playable is giving them 125 health, decreasing their windup time for attacks, giving them 500ms lights that deal 15 damage, and 700-800ms Heavies that do 30

Feats for Captain

Tier 1 - Conqueror, Body Count, and Captain's Lead (Passive: All allied Heroes deal 10% damage more damage when in a 5 meter radius of the Captain, Minions and Pike-men deal more damage)

Tier 2 - Chilling Stare, Inspire(Does stack with Captain's Lead), Fiat Lux (Knight) Smoke Bomb (Samurai) Bear Trap (Vikings)

Tier 3 - Second Wind, Captain's Crew (Passive, 3 Pike men spawn and follow you every where you go and assist in fighting, It takes 20 Seconds for each one to respawn), Pugno Mortis (Knights), Longbow (Samurai), Fury (Vikings)

Tier 4 - Stalwart, Morale Booster, Catapult (Knights), Arrow Storm (Samurai), Fire Flask (Vikings)

I made these in mind for the faction's specific feats and such, whilst including multi-faction feats, whilst trying to give the impression off that their a Captain.

Now for Shield Captains, they'll need a damage buff desperately, and an animation tune up, they currently have warlord's guard break throw animation, and their full guard animation desperately needs an animation change. They currently have a full guard and superior lights. For health, they should have 125 Health, with lights that deal 15 damage (20 if their a superior light) and heavies that deal 30 damage, their full guard should deal 20 to 25. They'll also need their attack speed to be sped up.

Feats For Shield Captains

Tier 1 - Fast Revive, Deadly, Captain's Lead (Passive: All allied Heroes deal 10% damage more damage when in a 5 meter radius of the Captain, Minions and Pike-men deal more damage)

Tier 2 - Juggernaut, Flesh Wound, Fiat Lux (Knight) Smoke Bomb (Samurai) Bear Trap (Vikings)

Tier 3 - Hard to kill, Heal on Block, Captain's Crew (Passive, 3 Pike men spawn and follow you every where you go and assist in fighting, It takes 20 Seconds for each one to respawn)

Tier 4 - Regenerate, Uninterruptible, Catapult (Knights), Arrow Storm (Samurai), Fire Flask (Vikings)

This is just a draft, or an idea that I had for Captains, and Shield Captains being playable, and the feats that they would have when in 4s. I went for a summoner type, due to captains usually leading minions in skirmish and story mode. For the different factions, ubisoft can approach this as being locked for your own faction, or being able to choose. I'd like for Captains to unlocked to everyone similar to recruit in Rainbow Six Siege. Again this is just a draft for them being playable.