As many people have already pointed out the role of you(the captain) is very ambiguous.
Could you introduce a roleplayer mode, for flavour, that you can choose at the start of the game?
This will let the player choose one of the starting companions as ‘captain’, meaning the player. A special icon is added to designate him in the inventory screen.
All you need to do is make sure that this character’s name is never used in any of the events. Instead, ‘you’ in events will refer to this character.
As a trade-off, it would be interesting if the death of this character leads to game-over, forcing players to either protect this character or simply put him in the reserve. Alternatively, a death of captain could let players choose the next successor.
Essentially, all the works needed are:
1. Remove this designated character from events
2. put a special icon indicating he is you
3. game-over or choose a successor to do 1,2 with the next character player chooses.
and this will improve the immersion of the game in terms of RP.