I dont think it's unoriginal. I think it's a nice step forward. SE just wants us to be more open minded. They thought with 12 "lets surprise them with a whole new set of summons!!"

Then its like "Omg, they're so whiney! Okay lets bring back the oldies in 13... But, make them radically different"

They're compromising with the fans =D

I think Ifrit will be fire and earth then.