Gunsmoke.... no, not the TV series, the smoke you get when a large tank cannon is fired off. A little puff of smoke (and dirt from the shock wave) of a large caliber gun going off would make a big difference in the AH2 GV world. Spawn camping would become more difficult since those spawning are looking for something other than your gun barrel sticking out of a bush - that puff of smoke gives away your position (as it should) and you have the option to either shoot it out or move. Aircraft coming into a tank battle might have a little more trouble picking out exactly what was what on a smoky battlefield, and it would enhance the usefulness of smoke rounds and smoke generators on your tank.
This could also be combined with enabling the TURN TRACERS OFF for tank guns. Instead of just following the tracer back to its point of origin, you might have to actually scan for smoke and pick your enemy out of it. Leaving the option to turn the tracer back on for long range gunnery is there for you, but again you give your position away that much more easily.
$.02
