PA uses M113 APC to deploy troops on ground behind tanks where contact with enemy is made. Then its foot infantry unloaded from APC and tanks who mount the charge at the enemy. The infantry platoons have AT weapons like RPG-7/9 etc to deal with enemy armour threat be it BMP or tanks, mortars like 60/81mm for indirect fire support especially against hardened bunkers and LMG for suppressive fire power. This way the dismounted infantry provides support with different types of weapons for the assault to take out different types of enemy targets.
While PA tanks take out enemy tanks or IFV with their main guns, the infantry screens the area and fights off dug in enemy infantry, saving not only own tanks from enemy AT ambushes but taking on enemy infantry as well as armour at the same time.
Remember infantry squad has more hands and is handling each different weapon independently, the tank can engage not more than two targets at one time, one from main gun, one from 12.7mm gun. The 7.62 auxiliary weapon rotates alongwith the main gun.
As the infantry and the tanks advance, the M113 APC stay behind at a certain distance, sometimes with AVRE's and other supporting equipment and commanding elements of the battle group. The 12.7mm on M113 is basically envisioned as an AD weapon. It can provide fire support under if made direct contact with the enemy.
when the enemy is routed from its position, the infantry sits back in APC's and the advance is continued alongwith tanks for next contact. The holding formations of PA are then tasked with defending the captured area while the advance continues with main armoured force.
Otherwise infantry takes back wounded to medical stations, collects prisoners and booty, digs in if ordered and deploys heavy weapons for defence of the area. The tanks are reloaded and refuelled. AVRE is used to bring back disabled or destroyed tanks.
The Tank destroyer based on M113 APC chassis is M-901 with dual ATGM TOW launchers, there are just 24 M-901 in PA. The other one is Maaz with Green Arrow ATGM based on Talha APC.
A company of Maaz ATGM can be attached with a mechanized infantry battalion where the threat of tanks is imminent but M-901 and Maaz are best used to bolster defence of an area against advancing enemy tank threat as being elf propelled they can reach farther faster without much delays of preparation and the job is simple, take out enemy tanks and AFV.
Operationally, assembling an infantry squad for this purpose, mounting on trucks, reaching the ops area, dis mounting, digging in and setting the ATGM in a defensive position takes more time. The biggest problem is terrain where the trucks have to travel, if its a road, trucks are faster, if its desert or fields, tanks and APC with tracked chassis are faster.
Problem with TOW and Green Arrow is that the firer has to keep guiding the missile towards its target by a controller. The instructions to missile are sent through a cable. So the firer is engaged towards one target till the target is destroyed.
Also M901/Maaz cannot fire on the move, need to stop and fire, kill the target then move. PA needs better ATGM now, HJ-9 is a good option.