Back to the OP´s question....advice on .375H&H ammunition for PG..
There are a lot of premium bullets for this round...but what do you really need..? I think it is far too much emphasis on bullets for PG...I have shot lots of PG with .375H&H, most with conventional bullets like Remington 270 grain core-locked.. I found them nicely expanded under the skin on the far side of the animals...kudus, wildebeests, oryxs..zebras.. If we talk premium bullets I will recommend 260 grain Nosler Accubond.. There is no need for 300 grainers for PG..eland included..
235 grain TSX are also excellent...I used them in Namibia for 200 - 300m shots..
I have shot zebra with .308Win. with 150 grain PMP ammunition...hardly premium bullets and guess what...the zebra died..
I agree with you on the over enthusis on using premium bullets for PG. However, hunters do need to use good quality bullets that retain most of their initial weight, produce a good "mushroom", and can penetrate through the thicker hide and heavier bone PG like eland, gemsbok, sable, etc. out to 200 - 300 yards.
I won't speak for others on the forum but the reason I suggest using 300grain bullets is simplicity and economics of reloading, and shooting.
Using only one bullet weight, 300gr, I can set my scope for 1 bullet weight, my solids and soft are set for same POI, and the rifle is setup for both PG and DG. I only need to but 1 bullet weight rather than 2 or 3 bullet weights, use 1 powder instead of having to buy and stock 2 or 3 powders and not having to adjust my scope when I change bullet weights. Of course I could simply adjust my powder weights to get the same POI for the lighter bullets, and use 1 powder that may not give me the optimum performance for the lighter bullets, but why?, when I can just use a 300gr bullet and save money by buying a good supply of 300gr bullets and 1 powder that I can use to shoot anything.
But then again I shoot 20 to 40 rounds of 375H&H (and 458WM) per range session several times a year. When preparing for an African hunt I'll increase my range time and the number of rounds fired from 20 - 40 to 60 - 80 rounds (combined) per range session shooting both solids and softs. Running 15 to 20 rounds of each through the chronograph per session to get better velocity average and ballistic performance data.
For the person doesn't reload and only takes their designated African rifle to the range once or twice a year, maybe. Then yeah, buying 2 or 3 boxes of factory ammo a year would be cheaper for them. Or if the person is preparing for a hunt and considers 120 rounds (6 boxes) of factory ammo is sufficient for range practice and to hunt with; I guess it makes some sort of economical sense to use a variety of bullet weights in both soft and solid bullets.