So, a howitzer is an assault rifle.
As are:
- Rabid dogs
- Expired milk
- Hospital bills
- Karens
Damn, everything is an assault rifle xD
I think you're focusing on the word "Assault" too much there.
The point is that they need to define what qualifies as an "AR". With "AR" being a complete term.
Just like you don't need to quantify the "Cottage" in "Cottage Cheese", nor "Saint" In "Saint Bernard".
Sure, if you pick apart names like that, the individual components of the name may not make sense, but that's just... Eh, pedantic.