Realistically, no, but the AT rifles in RO are intentionally cranked up, just like the grenades and artillery are intentionally cranked down, so the realistic penetration values are essentially irrelevant.
I agree completely. There's just no way to realistically implement tanks at the scale that RO takes place and have it come out in a playable state. Keeping with a historical ratio would have a single tank spawning once out of every 5 games, and with historical armor durability it would be the next best thing to completely invulnerable to infantry in a Stalingrad scenario. So some random person gets god mode once in a while...why bother?
Even if you're willing to accept a wildly unrealistic density of armor, you run into the utter impossibility of designing maps that play well for both troops and armor. Infantry need densely built up maps to make their ~100m engagement ranges interesting, and armor needs large maps with plenty of room to maneuver to make their ~1km engagement ranges interesting. Large AND dense, at the current FPS tech level, is not only a level designer's worst nightmare but also a sure-fire recipe for crippling game performance.
It's heresy to say it, but IMO, Tripwire would have been better off focusing purely on infantry.