Really happy for you!! Were I hunting a bull elephant instead Zambian PG in August, my rifle would be my .470. But as you say, the scoped .375 would be a step or two away.It also depends on circumstances
The .375 H&H rapier is great in orderly duels with clean deadly shots (spot & stalk), but not so great when things turn nasty and the focus shifts from killing to stopping, at which time the .45+ broadsword can become a lifesaver, just like the rapier never made it to the battlefield where cuirassiers wielded relatively heavy sabers.
Sure, as a client D'Artagnan you will have at least one PH musketeer to provide assistance, so you can adopt the perspective that YOU do not need the broadsword, although HE is most likely to bring one to the brawl...
Interestingly, there is ample evidence that the .416 occupies a somewhat ambivalent place: amply proven more powerful than needed for surgical killing, and also amply proven less powerful than desired for blunt stopping. I too had one when the mythical .416 Rigby was revived affordably by CZ, but I did not buy a .416 barrel when I transitioned to the R8...
I am sort of in-between. My largest barrel on the R8 is a .375 H&H (the rapier), but I love hunting the big stuff up close and personal with the double .470 (the broadsword) although I readily admit that I so prefer more for romantic than purely practical reasons. Oh well...
I was lucky to pick up a trophy bull elephant cancellation hunt in Zim this coming August at a price I can finally afford (dare I say Thank You COVID?), and I will have both rapier and broadsword. I will carry the .470 K gun with 500 gr persuasion in the thick jess around the irascible Zambesi Ladies, but one tracker will carry the scoped .375 R8 in case a dream 60 pounder walks across a wide clearing and requires 350 gr surgical attention...
And don't forget that while those Cuirassiers were making their ponderous way toward the enemy, Chasseurs and Lanciers were racing to the exposed flank.