When planning a close assault (even without suppression effects for vehicles), you should always try to chew up the enemy unit with all possible ranged fire first, and then commit to the assault.
Improved realism in the line-of-sight and spotting rules make scouting even more important. When going up against enemy armor or AT guns, always lead with infantry or fast, cheap scout cars to sniff out those ambushes.
Be very careful with the HQ supply rules, especially if you are unfamiliar with East Front. If you are not careful or used to dealing with supply in platoon-level games, you can find yourself high and dry very easily.