You should try DC. I don't use it for infantry but for AT guns and Tanks it can make a big difference. By keeping an eye on the mini-map you can see when a vehicle is coming. In DC you can have the right ammo loaded(AP or HE) and get off the first shot. Another thing that I do is look to see where the vehicle is going(mini-map) then select the nearest AT gun and target it. The gun will switch to the right ammo and take a shot as soon as it gets in range. When using DC with a Tank you can keep him in cover and pop out for a quick ambush.
When you get to certain "capture points" you should get a tank rush even on easy. I don't know how to make a mod either but I learned how to tweak my saved game files. Here is a link to a vid that shows how to tweak reinforcements,