It's borrowing from the physics of IGAU and trying to account for the different size/gravity of the characters. Which I think is pretty awesome. It only makes sense that big and small work like big and small ought to.
As Dr. Mayo said, SCIENCE. I am a fan of it.
Kung Jin is definitely the most obvious - and to me, surprising - example of it thus far. The dude looks like the big bodyguard type of their little clique; the girls and Takeda are all normal sized, yet Jin looks/seems like he's meant to be the heavy hitting powerhouse. But instead of going the usual big guy route like a Bane or Doomsday and giving him armor and mauling powers for days, they went the Lex Luthor/Kenshi route and gave him favorable range and space control instead. Boxy likey.