During financially better times, I was something of a caliber junky. I had numerous firearms chambered in a variety of rounds (most of which were sold during tough times).
Now that things are back on track and I can start saving for a few guns again, I'm taking a different approach: Only firearms chambered in 12 gauge for shotguns and .308 Win. for centerfire rifles (a .22 rimfire or two is a given, of course). Additionally, I think I only want as many firearms as I need to match any hunting situation I might encounter.
I think I can get away with only buying two or three more. The reduction in the amount of reloading tools, components, and ammo I need is an added benefit.
I have gone through a plethera of different guns and chamberings over the years as something caught my attention and then I lost interest. After a time I learned that a certain core group of cartidges and guns will fulfill my needs and interests and I've focused on those ever since. By limiting myself to fewer different cartridges & guns I was also able to stock more ammo & mags for those I do have, which is working out for me in the latest panic.
Looking at the link in your post, it looks like 12ga, .22lr and .308 will serve very well for your needs & interests, which is what I think is the important goal. Yeah owning more can be fun & interesting, but having the basics covered is the critical issue in my opinion.
My selection of weapons/ammo these days looks like this:
-.22lr, for all the reasons that .22's are always a great choice. Guns are a couple 10/22's and a Ruger LCR22 for snubby practice, fun & as a BUG.
-.38 Special +p, for my CCW guns. Guns are a Ruger SP101 & KLCR, both chambered in .357. I expect at sometime I'll get a longer barrel gun but it's not essential.
-9mm, for defensive use, target, whatever. Guns are 2 Glock 17L's and a G34 that I bought when I had trouble finding a second G17L.
-.223/5.56, for defensive use, target, varmints, everything I need a centerfire rifle for where I live and for what my interests are. Rifle is a flattop Rock River AR national match with a 3x9 scope in a QD mount. No rifles for big game in Ohio, so it does what I need & want.
-12 gauge, for all the reasons that a shotgun is always a great and versitle choice. Guns are an FN SLP with screw in chokes & ghost ring sights that handles buck shot & slugs superbly for what ever need, hunting or defensive. Also a Browning Cynergy O/U with synthetic stock & full camo for all other shotgun needs & interests. My redneck pride & joy.
-.45 Long Colt/.454, mostly for hunting deer here in Ohio but also for a hoped for someday trip to Alaska. Guns are two Ruger Super Redhawk's, a 7.5" for hunting and an Alaskan for fun and the someday trip.
Probably everyones choices for what works best for them will vary somewhat based on where they live, what shooting opportunities they have, what needs they feel they have and what direction their interests take. Guns are useful tools, plus I find them fun and very interesting. Still, I only have so much money, resources and room I can devote to them no matter how much I like them. My collection fits in my safe with a little extra room to add a couple more if I want. For this part of my life, thats plenty. YMMV