To the issue of akrasia, I don't see this as a case. My own judgement says that a life like theirs is vapid and devoid of meaning. Fighting to the death against one's own best judgement probably isn't rare either; I expect many, many soldiers have died fighting wars they despised, and who had options other than fighting them. In effect, I feel like this is multiplication by zero, and add infinity. You have more at the end; you're just no longer the unique complex individual you were, and I could not bear to submit to that.

And you think that not being able to bear submitting to that is wrong?

Personally, I'm one of those who prefers the assimilation ending, there are quite a few of us, and I certainly wouldn't be tempted to fight to the death or kill myself to avoid it. But for a person who would fight to the death to avoid it to say that assimilation is optimal and the True Ending is senseless seems to me to be incoherent.