You are correct as always, but you dont tell the whole story. Tanks was the most successfull unit when attacking, yes, and that was because they could easily breakthrough the enemy lines, exploit the new situation and backstabb the defenders. This type of warfare produced less casualties than the artillery barrages, because the defenders surrendered fast when encircled by tanks, compared to dug-in defenders that was annhilated by artillery barrage.
During WW II:
65 % of the casualties was killed by artillery shells.
15 % was killed by small infantry weapons.
10 % was killed by tanks.
10 % was killed by planes.
There was a reason they kept producing artillery during WW II, even if they got tanks. The artillery was the cheapest way to kill enemies, because a Tank cost three times as much to make.
I agree with you this “boost” thing just clutter the game. It will make for a cleaner game if all units have a set value that dont change with modifiers.
Inf, or Mech, dont need a boost in attack, because their main object was to secure and defend the other arms.
In WW I the idea was that artillery should kill the enemy, and the infantry should move in and take control of the terr.
In WW II the idea was that tanks should break through the enemy line, and Mech’s should follow to protect the tanks from enemy infantry.
In both wars, the artillery was more successful during defense, and that should be recognised in the combat value.
I suggest:
Inf att 1, def 2 and move 1
Mech att 1, def 2 and move 2
They get no boost from other units, because infantry divisions already got inherent artillery and engineer support.
Artillery att 2, def 3 and move 1. Basically a defense weapon.
Tanks att 3, def 3 and move 2. Basically a Blitzkrieg weapon, so it should be able to one additional move after combat in the first territory. It should be allowed to retreat back to friendly territory after a strafe attack where the surviving infantry are stuck, or it should be allowed to continue attacking next enemy territory.