#1 EC3 (RAW)
EC3's first stint in the company doesn't boast much credibility to be discussed, and he mostly came into the limelight due to his run with TNA / IMPACT Wrestling where he portrayed the role of IMPACT's President Dixie Carter's spoiled nephew. He became a two time TNA World Heavyweight Champion and one time IMPACT Grand Champion.
His NXT resume is quite thin and it doesn't seem that he would be featured in the NXT title picture any soon, which could have been the reason for his call up.
Coming back to the selection of brand, EC3 is a fit for both the brands but RA at this moment needs EC3 more than Smackdown. EC3 is filled to the brim with charisma, and has the mike skills and technical acumen in the ring to back himself up, which RAW is in need for its mid card and upper mid card.