I put three handguns on my permit for several reasons
1.) I could not put any rifles on it
2.) I could not put more than 3 handguns on it
3.) Different situations call for different carry options(smaller handgun for itp deep cover like summer time shorts/shirt carry vs. winter time otp carry full size 1911 with a jacket etc)
4.) Stopping power(.45) vs. firepower(9mm)
5.) If you have to use one of your handguns to defend yourself you may never see it again, so you'll need others on your permit that you can carry immediately until you can replace the one you just lost.
As far as that walther p-22... I wouldn't bother. When I used to have mine it seemed like it would jam more than it fired no matter what ammo I used.