I think that you and your wife are doing what you should with purpose and are doing it perfectly. IMHO, the only time it is justified in being random about what handgun you are carrying is if your odds of ever needing a handgun in a serious situation is over 100 to 1. The other situation for working with two different handgun is if you work daily with a partner and the two of you are regularly going into possible deadly situations AND you partner insists on carrying a revolver as to your semi-auto. Then you both should practice with the other's type handgun to the point that you are competent with the other's gun in a pressing time of need. .............