I'm more of an AND kind of guy. If I were doing what you are doing I would load some 250 grain barnes ttsx for the plains game. It shoots just about as flat as a 300 win mag with 4477 ft lbs of energy at the muzzle and top it with a 2x12 vx 6 if it fits without hitting back sights.
I'd then load up a bunch of 300 gr tsx for the buffalo and have my 1x6 vx6 for buffalo.
I think you mentioned you had Talley QD mounts. You can have the best of all worlds this way.
I used a Leopold VX6 1-6 on the Sako 375 HH I rented in Africa. Longest shot kill was 140 yes. I took a shot in brush at 185 yes but had it deflected & missed. I felt no handicap. I just ordered a Sako Kodiak 375 & plan to put a Trijicon Acupoint 1-6 with the single post & green tritium triangle.
Mule deer and Colorado elk seasons almost done! Hunters driving farm roads, looking for racks, their PH driving them along, I ask that you not pull into my drive. The buck behind me, on the boundary line of the GMU somehow knows. The hunter laughs, I would invite you in to see my Searcy rifles but social distancing prevails, darkness arrives and the buck slides away into secret tree grove...