"whole squad of stingers"
It's true, I play infantry, and as soon as I start getting farmed by vehicles, I have to swap to Engineer or quit. Usually it's stingers, because on the bigger maps, it's easier to block line of sight to a tank than a plane/chopper, and they can take mines for tanks.
Recon can paint targets, that's a great assist for Stingers too. I main Support, so I'm just screwed, my LMG won't do anything to vehicles - I resupply the rockets, or I'm fodder for vehicles or snipers.
You're probably seeing squads of stingers because no infantry wants to be fodder for vehicles.