Well just because it is seen in a video, may not mean they can effectively engage the drone, etc. E.g. in the Army we were trained to lay down on our backs in a line. With everyone firing up in the air in the direction the aircraft was coming. And let the aircraft flying into the "wall" of fire. That was better than nothing. But you may get lucky ?
Of course, our MGs, e.g. M60s and later M249 SAWS, would try to engage the aircraft as one would expect. Generally, an MG has a high ROF than an Assault Rifle, etc. Light Infantry Cos. like when I was Plt Ldr with the 101, we don't have heavy MGs. As when I commanded a Mech unit, with M113s. E.g. the M2 .50 cal., which we generally always kept mounted on the track. But even then, the .50 cal. was not on an AA mount however, still could engage aircraft.
Something about AA fire, if you put up enough firepower, the attacking aircraft may try to jinx and avoid being hit. They would see the tracer rounds, etc. Which may make them miss their target. Or they may just abort to avoid all the fire.
Drones may react in a similar …
Bill makes a good point the troops riding on tanks may not even see or hear the drone(s) and by the time they do it will be too late. If you ever have been on or in an AFV, they make a lot of noise. Plus, generally you are holding on to something. So, you don't fall off, as if the AFV bounces across certain types of terrain.
Especially at night, if you fall off, the AFV behind the AFV you were on, etc. … you could get overrun/killed, etc.
So even with NVGs you may have a hard time spotting a drone. IMO the best weapons to take out a drone is the MG mounted in front of the TC's hatch. But the TC may be too busy to effectively use it ? So the Infantry riding on the tank may help ?
Another thing to consider, is if the tank is moving you will have a harder time hitting the drone(s). If you even can see it. Just like it the Cowboy movies trying to shoot accurately from a moving horse is generally a waste of ammo. Of course, a horse can move faster than an e.g. MBT. But firing from a moving vehicle is still challenging.
Plus, larger drones like the US Reaper and Predator may be too high to see, with the naked eye, etc. You may see the Hellfires, etc., incoming ordinance but again by that time it will be too late.
The smaller lower flying drones we see being used are much smaller than those bigger drones. Of course, the smaller size may make it harder to hit. They could even use terrain masking like a helicopter does. Hiding behind tall trees, etc. Then striking again by that time it may be too late.