Board Thread:Manga/@comment-5774380-20160814045452/@comment-5774380-20160814201657

There are obviously scientists in the Hometown, and Zeke is either one of them or has first-hand access to their technology; evidenced by his ability to create Titans in Ragako that seemed to be more "avanced" than the typical ones, as they were capable of moving at night and he created them seemingly without direct contact (a gaseous form of the Titan Serum?). His ability to control the Titans seems to be a primitive version of the Coordinate; but it's obvious that it's not as powerful as the Coordinate itself because otherwise they wouldn't need to go to such lengths to retrieve it. And let's not forget that Grisha remembered that he was already a doctor when he arrived to the Walls.

I think the Hometowners either stole part of the technology of the "nazis" or created their own version, but despite their progress, the Coordinate is the only thing they cannot replicate, and that's why they need it so badly.