The chance to not shoot down goes down dramatically with 4 guns, but you are still in a situation where a plane can do an entire pass without being hit on a regular basis, which is unacceptable considering the AA HT's high investment cost and its only non-meta option Soviets have to deal with air attacks. Against planes that don't loiter this is an even more glaring problem.
I never claimed that the changes WBP on Quad are bad, I have not tested enough. Although a X3,333% buff sound a bit big.
"Increased the chance for the Quad to take down an airplane from 30 in 10000 to 10 in 100"
Allies also have non loitering planes.
Soviet have "skill shot" planes USF have "skill shot" planes. Skill shot planes are not meant to be shot down before attacking. they are countered by moving out of the way.