I believe the ability for Div 3 teams to recruit MPP Bosmans is intended to support them in their efforts to rebuild/gain promotion. A Div 1 team paying a small/affordable fee completely negates that.

Bosmans can be traded. Why not offer a division 3 team a trade preseason? I've done it before.

As for numbers and usage - 3 teams have 5 MPPs, Kilmarnock, St Mirren (with 4 DMs) and my Stirling Albion.

My idea which is still a work in progress is to play BC with as many MAs as possible ( I have 5) this was intended to help with goal scoring from midfield. But it'd hard to keep all players with high enough SL to make it work.