Project 37 uses a lane-based movement system that allows units to move with greater autonomy. Just build the units and they'll figure out where to go.
Focus on getting the right units out at the right time. They'll call for transport to the enemy beachhead themselves.
Does the enemy base need a few of your battleships in it? Yes. Yes it does.
Decide if you want to overwhelm your opponent with hordes of infantry, build unstoppable tanks that can run over enemy vehicles, or sit back and decimate them with airstrikes.