So, now I am thinking a scoped 375 H&H for the medium and the 458 Lott for the heavy.

Mostly, I am thinking this, so that i can use the 375 with Solids for croc and, if i have to take it in the water, hippo.

Do people typically shoot the croc and hippo with solids? If so, would 250gr solids from my .338 be legal and sufficient? I don't know if I can get them to pattern with my softs, but it might be worth trying.