Wehrmacht infantry gained heroic armour at vet 2.
To be precise, they gained 'elite' armour. Heroic armour was in the game yes, but it was used by knight cross holders and officers, for example, but not regular infantry.
The armour was more complicated in CoH1 in general. Armour types like 'infantry', 'soldier' or 'airborne' all had their own attributes and damage tables, for example. Not like the single armour value in CoH2. This can be a good thing, as balancing the infantry survivability is, if not easier, more straightforward and less time consuming.