Well here goes my process, watch folks get bent outta shape over this one :P
There is no discernable difference. My guns all run just about everyheadstamp under the sun.
IF, and this is a big IF, you REALLY want to walk the edge of pressure, then you better stick to a make; honestly you should stick to capacity. MOST folks will tell you to weight them. Nice try, but IME the weight "should be" and indicator, but it isn't. Weight is dependant on alot of things, that MAY OR MAY NOT have any relevance on actual capacity. If you want to know what something holds, weight it empty, fill it, weight it, do the math, VIOLA!!

My 10FP in 308 that I use for 1,000 yard shooting has at least 4 different headstamps in that load. My load is seated about 1/64" off the lands(my gun) shooting 175 SMK's, with Win 748. I'm about a half a grain off Sierra Max book. NOT max in my gun, but chrono's 2550 with very low ES/SD on 5-shot groups. That load with mixed headstamps holds MOA at 1,000.
Especially if you have fired them in YOUR gun, and you neck size; the capacity should be pretty much the same anyhow.
Do what you want, but I have mixed headstamps for the past 20 years without issue. 204-223-243-25-06-30-06-270-7mm-6.5*300WSM-338WM