With that many Creedmoors in the house, I can see a solid argument to stick with the 6.5CM. The 6 ARC (in my opinion), seems a bit underpowered for anything bigger than deer, and (though slower 223 and 308 powders work) to get the most velocity out of it you need something a little to slow for most 308/223, but too fast for Creedmoors. (that is assuming you reload)
If you don't reload, then with all the Creedmoors in the house, you can likely make the math look like you could save money by reloading (though in reality you probably will just shoot more instead).