several playable characters fit but 40 year old tommy, current claude, 30 year old CJ, 48 year old toreno, 9000 year old avery, 50 year old rosenberg, an aisan guy, another white guy, another black guy, another indian guy, another arabian guy.
and that wouldnt mess up the plot, make it go with the story, not choosable players, just players that you know at the current time that you can play as and do there current missions. My idea would either be to have to play as that character until you finish someting or if you go to there house and go into a marker and change to them, maybe your old player will say"i gotta rest for a while" and your new character will say "yeah i need some outside time" or smuthin like that.