Board Thread:Theories/@comment-26624146-20170623033404/@comment-1327106-20171021202204

Well, Eren has more than a year. :)  He got his Titan in 845, and it's now 854, so he's got four years left before he hits the 13 year deadline.

I suspect the others are out there, but haven't been seen yet. Eren can drawn on his memories from Grisha on how to behave in Marleyan society without asking basic questions (and even then he got the armband wrong). The others don't have that kind of advantage.