I'd want Simmons to start at Clearwater, let his hitting tell you when he should be promoted.
I like the ML changes, I think they were doing marginal talents a disservice by allowing them to hang around the minor leagues indefinitely instead of getting on with their lives, and from a development standpoint, there are only so many competent coaches you can find (even if money is no object), so you want to focus their efforts on "legitimate prospects." A lot of players were being drafted/signed out of LA just to fill out rosters with no real future.
By condensing the minor leagues, you improve the quality of competition, which should improve player development. There simply isn't enough talent for any team to field 2 DSL teams, 2 GCL teams, a A- short season team, etc.
There are still 100+ slots in the US, plus LA leagues where kids can marinate before you bring them over. And you can stash guys in extended spring training, IR, etc. if you think they need a couple years to physically mature.