I personally hunt tanks down, not very many escape but you should be packing proto Swarms with advanced+ nanohives if you wanna deal with Madrugars alone. Madrugars with reppers and hardeners are the worst, you gotta stay on their ass or the mods will cooldown and its back to square one :/
Gunnlogis aren't as bad to deal with despite having so much shields, but thats because 99% of Gunnlogis run at the first sign of AV ironically despite Gunnlogis having the advantage over AV so working a Gunnlogi to a suitable location isn't that hard
If your a Forge Gunner, you shouldn't have issues with tanks so long as you have a good spot to see'm
Don't expect to be reliably able to kill an enemy tank solo. If there's one tank vs. one AV player, and both are similarly skilled and have similar quality gear, a cautious tank driver will probably survive. A good AV player doesn't expect the kill every time, but they can take the tank out of the fight pretty consistently. If the enemy tank ends up going 0/0 because of you, then you did a good job.
Solo'ing tanks is depressingly easy if you get up high use proto swarms and few damage mods, the rendering means the tank can see the swarms so they get no warning meaning the first shot is free and by the time the first one hits you have got the other 2 sets in the air. Reload fire 3 more and 9/10 +150.
Or get up high use an assault forge gun and destroy anything and everything.