Those are some good ideas. When I bought MA, it came with a ton of 25mm x 50mm and 50mm x 50mm bases and the game was bases on using those bases. When I sell the Army, I usually include 4 infanty to a base or 4 cav.
You don't have to have 4 cav to a base, because really, it's the base value on the card , not the visual of the minis. Does that make sense?
Can you play this game based DBA? Yes you can. I think the simple rule is opponnets need to have the same size base.
Tournament play is something I am trying to figure out. Right now, Some of the playtesters are using DBA armies taped or stuck to the MA bases. Hopefully, I'll have more info soon.