We could make it a bit clumsier than it is currently. Also seemingly following the trend of every single game/mod with a PIAT excluding half the reloading steps for it it may have to be made less powerful. But then again those tanks were panzer IIIs. 3 rockets I would say is enough to be carrying around. It's short ranged and has quite the drop off. Not to mention you would be getting shot at lots.
The PIAT in reality was regularly fired from the hip. It was an AT weapon you could literally leap out of a building, do a 360 and shoot a tank with. It had no propellant. However it had many issues such as falling apart when fired, having a 1/4 chance of being a dud and needing to hit on almost a 90 degree angle to do any damage with. The falling apart could also mean it could blow up in your face. Some troops prefered hip firing the 2 inch mortar at tanks as it was considered safer, it almost always detonated, had greater range and felt far more satisfying to use even though in practice it did even less damage. Just consistently less damage.