There is the fact that the WW's 20mm can't be much more powerful than the Il2 23mm. The il2 23mm can be taken in by fighters without dying or often without even losing parts.
The WW's range will probably be 1.5K, after which the bullets just disappear, just like every other round smaller than 40mm.
If you can get within 2K of a tank and not die shortly after, you're either very lucky and in the far end of the bell curve, or you've got a clueless player in the tank.
The only tank I see the WW being trouble for is the M4. Oops, the M4 has the flatest ballistic and one of (if not the) the punchiest rounds... No joy with that one either, unless the pilot is deaf and blind. Maybe a kill on the pintle gun.
The fact is that (unless I'm mistaken) the WW will have the same sort of turret protection as the ostie. You don't just waltz into a vbase on your own with those. You do lose your turret very easily... it just takes a few 50cals or well placed 303s, or even a single round from an M8 in the right spot.
The only unknown is the 20mm ballistics and lethality, which is part of what you're basing yourself on to say that it can walk into a vbase and tear it all down unharmed and needs to be perked.