If axis' infantry catch you out of cover you probably lose engagement
So hug covers and builings all the time.
This
When infantry sections (IS) are in green cover their damage per second (DPS) is equivalent to always shooting the enemy at point blank range even if they are far away. The opposite is also true. If they aren't in any cover, its like they are always firing at the enemy from max range. Even if they are standing next to them.
Use cover or lose. As already mentioned, Brits in buildings are death. Especially early game. Use your first IS aggressively and see how easy map control becomes.