There's a difference between what's allowed in tournaments and what's intended. I seriously doubt that, when they designed the USF, Relic wanted vehicle decrew to be used as a means of circumventing population restrictions.
And yet, they did.
They have said so themselves that it is INTENDED DESIGN DECISION.
It means its allowed AND intended.
Same logic applied when PTRS spam was great at killing infantry. Not an exploit per-say, but definitely not what Relic intended either.
No, not even close.
There is a difference between balance and features. Abusing OP unit is simply that, abusing OP unit until ifs rebalanced, every single patch had its own.
Using INTENDED army feature is playing the game like relic envisioned and balanced the army.