The whole combat system has been revised from Tank Battle: North Africa. You get a better idea by looking at the unit factors in help and by using the combat information option see the (i) on the screen. You can see all the combat differentials. Click the differential data to get an even more detailed description.
Move and shoot has a lot of variations. In general Soviet units get more penalties than German units if they move and shoot.
Hull down now works for units on hills against units no on hills.
There are virtual hill crests depending how far a unit is across a series of hill hexes.
Woods are cover for all units.
Strategic movement has been added so units move faster if at least 4 from the enemy.
Burning buildings block movement.
Artillery can mount and dismount.
Added hmg units, mortars, flames thrower infantry and flamethrower tanks, and rocket launchers.
Entrenchments are now hex side based rather than hex based.