in CoH1 a cover had a great factor on units because they were dying much faster with lower health units. Rifles crossing red cover were usually losing like 2-3 man in few secs, in CoH2 cons will lose maybe one guy and will reach enemy units.
This is true, in CoH2 the only 'low health' unit is Osttruppen. To give an idea on the health differences, if American Riflemen from CoH1 were 'grafted' into the game without changing anything, they'd be roughly on-par with Osttruppen!
Rifleman Health: 55
Osttruppen Health: 48
Everything Health: 80 (And yes, from Pioneers to Shock Troops, they all have 80 health)
It also looks like the armour system was simplified, and not in a good way. To elaborate, CoH1 had Infantry Armour, Soldier Armour, Elite Armour, etc. This allowed anything to be balanced against anything. Panzergrenadiers took extra damage from Engineers to balance the early game, on-par with Riflemen, despite Riflemen being extremely superior to Engineers. This made the game easier to balance because every unit could be adjusted vs other units. Without it, OF would have been an unsalvageable mess.