From: Adelaide, SA, Australia
I see no-one has answered this yet.
The difference is that at full strength, they do NOT have the same combat strengths!
Infantry are the strongest of the non-armoured.
Next is Motorised Infantry, only slightly behind the regular infantry. (it has more AC but less artillery, and can also keep up with the Armour.)
Next is Cavalry, has less support units than Motorised, but even more Amroured Cars; And is also capable of keeping up with Armour.
Next is Mountain Infantry, has less of everything compared to Regular infantry, but does have winter warfare and mountain warfare bonuses.
Next is Luftwaffe, Amout the same maximum size as Mountain Infantry, but without the combat bonuses.
Next is Airborn, slightly smaller overall than Luftwaffe troops.
Last is Fallshumjager? Divisions, even smaller than Airborn.
Note that Luftwaffe, Airborn, and Fallshumjager have no combat bonuses, the should be regarded as weak infantry units, and ideally used only for partisan suppression, garrison requirements, or if you are desperate for combat troops to fill gaps.
"We're having a war, and we want you to come!"
So the pig began to whistle and to pound on a drum.
"We'll give you a gun, and we'll give you a hat!"
And the pig began to whistle when they told the piggies that.