But Gerrard has done 3 years as a first team manager. Whatever your views on the strength of Scottish football, he is far more experienced than Morison.
And he is going from a club where he still had 2 1/2 years on what was undoubtedly a lucrative contract. He would obviously not move for a contract that ran just until the end of the season.
Morison on the other hand is completely untried at first team level. And I would guess (or hope!) that he has been told he will still get his old job back if things do not work out