I think you make a really great point espcially about keeping the guns similar to each other. I think I need to expand on what I was getting at when I said "I've noticed with myself over the years that the more guns I have in my safe, the less I know each one."
When the gun cabinet was getting full I never felt like I didn't know how to operate each different type of gun, or how it functioned. The part I didn't feel like I knew as well would be the ballistics of each different gun. Knowing how the ballistics of my guns has been a new evolution in my personal shooting because I started going to a range that has targets farther out. All the rifles in my safe are completely mastered when it comes to shooting at 100 yards or less, but at 200 yards I didn't really know what the 30-30, 308, 223, whatever would do. At 100 yards there isn't much concern about wind, temp, humidity or whatever else and that's fine because that's where about all hunting takes place anyway. In my mind I was having a hard time keeping track of "well this rifle does this and that rifle does that". I'm more or less trying to use the K.I.S.S. method so I can keep it all straight in my mind.
Now I know how my 30-06 will handle in different winds at different distances and where my hold overs are. Knowing that kind of stuff has made me a more well rounded hunter and I freely admit that I have more to learn. I'm constantly reminded that learning to shoot farther and better for hunting or targets is a journey and not a destination.
For me the joy of a full cabinet used to be variety of actions & calibers. One day I might feel like an AR type of day, or maybe a lever action kind of mood, or a single shot, who knows. The variety is what made shooting fun for me, but now I've just really been bitten by the longer range bug. I'm not shooting for competition or money, I just really enjoy the challenge of it and friendly competitions.
I completely agree with the idea that I need a 22LR too!

Seems like the ammunition guys are trying to compete with the gasoline guys with outragious pricing. I've been reading up on the GSG-5 22LR. It looks like a fun gun, but it's going to have to wait. $500 is too much for a 22 for me these days.