A leapfrog approach works rather well, though it does wear down the armor. Depending on your tastes, running supply trucks back and forth may either be tremendously entertaining or horribly boring. I found it amusing. Hur hur hur. Infantry, however, is the one problem I had in-game.
Every single individual is represented by a little man.
Telling them apart requires clicking on them. Yea, it can be overwhelming. Organizing them into platoons or squads is somewhat effective, but they don't tend to work well together. They would do better with a Ground Control -esque squad system for the infantry units because, with 1,000 or so units, it can be a tad overwhelming. The Campaigns are all incredibly difficult multi-part missions, usually against some steep odds.