alex0535, I am glad that you got out of that OK but I still feel safer being a mediocre shot than a prolific cusser.
A large majority of people can find a 9 mm pistol that they can shoot accurately, comfortably, and rapidly. A .22LR pistol certainly can be effective, but a person has to be much more skillful, with a measure of luck thrown in, to be as effective as the same person with a center fire pistol.
If you are going to use a .22LR, you should probably fire until empty and look for an opportunity for a head shot somewhere along the way. Absolute answer to your 3-to-1 question would depend on placement. CNS shots: probably yes. COM shots: probably no, at least with regards to immediate incapacitation of an assailant.