I'm not so much a gun expert as a hunter. Many of the cartridges like the 45/70 and others have a strong following from people that really have a passion about them. If It's legal I will take you with what ever you like. I have no dog in the fight where your personal choices are concerned.
I know what I have seen work great and what I have seen appear marginal. It's what I base my feelings on. I'm not reading charts or graphs and making my opinions up based on formulas and other theory. For those who choose to use that information Great, for those who choose to blow it off because they feel otherwise, good for them. I simply don't care what people use, it's their hide in the ringer and the PH will settle up the mess one way or the other. Or maybe the emotional choice they make prior to the hunt will cost them the lost trophy they have dreamed about. Who knows.
DG cartridges for a serious meaningful minimum for backup are 500 grains at 2100fps, better then this is great up to the point of recoil overload.
For hunting the 375HH with a 300 grain bullet at 2550 is also established. I've found that the 270 TSX at 2800 is even better, but it's still the 375HH.
If your choice falls between these two then it should be fine. If it does not and folks wants to market their opinion of why it's so good, then have at it, but I won't be buying that sales pitch any time soon.