Since Jean drew Mikasa years before he even met her and Eren's power is beyond the concept of time, what if Eren actually put the idea of Mikasa in Jean's mind because Eren knew Jean would be the best person for her after he's gone?
Funny thing is dudebros are saying Mikasa looks like "mankasa" now that she literally has MORE REALISTIC body design than ever. Just say you never seen a woman's body in real life and go.
Can't blame them, though. Why would women want to get close enough to be seen with losers.