I havent worked this idea out in detail, but here is the bare bones.
To introduce more planning and less luck in the reinforcements (I always try to reduce randomness), have a system whereby you have a set value of reinforcements and you can select the exact units based on values.
tank: 5 inf: 2 art: 3
tank: 4 inf:2 art: 3
decide what reinforcements you want at the beginning of the turn, like in the other versions of A&A, and recieve them at the end still.
I will work out the total values and post them soon.