My 2c, with a bunch of assumptions....
It's your first trip so you want it to be memorable (and it will be) so try to get some of the iconic animals. This can mean different species to different people, and you've indicated a few species that you'd like (more thoughts on that below). The location may play a role too - do you want traditional savanna (TZ, most of Zim & Zam, much of SA), mountains (SA - E.Cape & Nam), thick bush (SA - Limpopo, Moz), semi desert (Nam, SA - Kalahari)? I am generalizing big time but you get the drift. Your physical abilities may dictate too. You're traveling a long way just to get here, so spending precious time traveling between different terrains to take a somewhat arbitrary selection of animals would not be a great use of resources - sticking to on location and maximising your time there would be my vote. You could then choose a different region (with a different set of target species) for your subsequent Africa hunts!
If you select a single location, then that starts to filter your species list. My suggestion would be to choose maybe 3 primary species in that location and then add some 'species of opportunity'. This would also keep your budget in some kind of control and you wouldn't be spending money on unnecessary travel. For example - Limpopo, SA: primary targets kudu, Blue Wildebeest, zebra, croc. Secondary species - impala, warthog, baboon. Or Namibia in the semi-desert: primary game gemsbok, mountain zebra, eland. Secondary: springbok, hartebeest, maybe warthog etc.
Yes there is lots of species overlap across regions and you'll get many opinions about being able to shoot just about everything in one location (obviously many introduced species in that case). Your pick.
That would also help you narrow down your rifle of choice for the hunt - bushveld hunt will be better with a handy rifle and a bigger, slower bullet. Open plains would predicate a flatter shooting calibre and so on.
Hyena and croc will be expensive and both are fairly specialised hunts, depending on where you go. I think you'd get a lot more bang for your buck taking more antelope (which I note you don't list at all) than hyena and croc for your first visit. Hyena and croc will also limit the potential locations because they are not so commonly available on licence around Southern Africa.
Baboon and to a lesser extent warthog are considered vermin in some parts and generally not the primary focus of a hunting package, i.e. they are usually more by-catch or targets of opportunity. They are also not costly so if you choose a location with decent population density you may get to shoot multiple of each. But if you wanted a trophy hog then you'd want to steer clear of locations with harder ground because tusk size will be limited and it would be a harder hunt for sure.
Zebra are pretty ubiquitous so you will likely find them in most locations, so they won't be a problem.
Your rifle choice is 'fine' - personally I'd tailor it once you'd narrowed down your hunting venue and species list. A 300 mag or 338 (or even 7mm) would be a better choice for the species you mention, for example. If a 375 is all you had and you can shoot it well, then all good. This forum is bloated with calibre discussions already
