So its ok that allies can spam one Unit and gets big profit and less micro...while axis need combine arms and much more micro. I know why i dont like allies spam play...and why its bores me.
Are you dense?
In the very post you've quoted I've compared it to allied unit of the same role, which you've guessed it, can NOT be used as mainline infantry, because it serves the exact same role of force multiplier.
Different units have different roles.
Just because the unit got 2 legs and 4 or more models does -NOT- make it a mainline infantry.
OKW got 7 different infantry units.
Why do you have such a hard time comprehending that not all of them exist to fulfill the exact same role?