The recent operations of the Tang Army's Armored Corps had been quite monotonous, as they lost the opportunity to make rapid flanking maneuvers and surge forward aggressively. They could only follow the infantry, slowly squeezing forward, inch by inch advancing.
This was completely at odds with their previous tactics, and left them somewhat at a loss: The prefer the unrestrained rush forward, and were not particularly interested in covering infantry.
Thus, equipping infantry with assault guns was actually a relief for the Armored Corps, freeing them from the heavy burden of supporting the infantry.
Moreover, the senior commanders of the Tang Army were unwilling to sacrifice tank units in siege battles. They preferred to let these armored units run like cavalry, strike the enemy like lightning, encircle and destroy their opponents.