It'll be nice if you can ditch crew after the initial choices.
But as it goes, you won't get "replacement", you will just get less contents.
This is not a RPG that balances around game-play, this is essentially a porn VN with heavy RPG elements.
I like the idea of limiting crew-member you have to choose for gameplay purpose.
But not for a Porn game - I prefer collecting harem.
Also, the problem is not "You are forced into Rylan and the Doctor", but the severe unbalance of available contents for each crewmember.
Like I'm not interested in Rylan and Arthur, but I never felt they are forced upon me, I barely interact with them, in exchange, I get far less contents.
(Kindly reminder: This game shifted focus onto human / human-reskin a long time ago
)
BTW,
Why TF did the dev implement a Real Life Time Quest system? Is he trying to make us play daily? Do our "Dailies" in this gay porn game???