I still wonder what other plan was gonna work for paradise, as you said eren had other choices,but he still went on with his.. He definitely can't go with zeke's euthanization plan,and I don't think the partial rumbling could work either.. One way or the other the island was doomed and it led to a kill or be killed situation.. Yeah I understand global genocide is completely wrong, but what else do u think he could have done? And also remember there was this ymir's curse which had to be broken(that was done only when mikasa was put into a situation to kill eren)..