I made 2 skill setups for my MMAs, so I thought I might share them.
The first one is for the suicide MMAs (1R attacks, 220R, 220B or sacrificing C, knights or Mounted Marksmen):
Rapid Fire: 3
First Aid: 3
Jog: 3
Navigation Crash Course: 1
I don't have a great need for Navigation Crash Course, but it can speed up lootspots and I would feel that a book invested in Juggernaut was a waste.
Unstoppable Charge: 3
Just a Flesh Wound: 3
Garrison Annex: 2
Confident Leader: 2
I'll probably have 1 MMA with 3 in Garrison Annex and 2 in Unstoppable Charge (for R and B attacks) and 1 MMA with the setup shown above (for sacrificing swift units).
1-Up: 1
Again, as I have a few MMA, I'll probably have Master Planner on some of them and 1-Up on the others.
Battle MMA:
First Aid: 3
Jog: 3
Overrun: 3
Navigation Crash Course: 1
There are only a couple adventures where I use MMA against bosses, but since I don't use B on MMA, except for suicide, and the other skills available didn't seem useful, this was my choice. Of course, more books in Navigation Crash Course might be preferred by some people.
Unstoppable Charge: 3
Fast Learner: 2
Weekly Maintenance: 2
Garrison Annex: 3
Master Planner: 1
I'd really love to hear other people's ideas on this. Thanks!