You're right but that takes a long time in my experience. The other issue is that the cuts inside preferred move can't be taught and, from what the OP seems to be saying, that's required to make this work.
Honestly, I'd love to play with this tactic but there's such a dearth of quality players who can play the MR and ML roles the way you've described them and - since I play FM Classic - I can't train players to play these positions. Unless maybe I've misunderstood the requirements?