Having options is always a good thing. And being a Safari hunter from KY, we are almost neighbors, lol. What you tell your wife (or not) is totally your business. My practice is simple - I never hunt Africa with the same rifles twice. Why? Well, to me a rifle that went to Africa with me and served me well has now become a priceless heirloom and earned a right to be displayed on a wall. So, for each Safari, I work up and prep two new rifles. Or two nice used ones. One for PG and one for DG and larger PG.
With three nice DG rifles, all you will need is three more nice PG rifles to complete each battery. So far, I have used 308 and 7mm/08 for those roles. The 338 WM is a nice load. Kicks like a 375 lite. I just got a 338 RCM which is the compact version. It is light and handy and weighs only 6.5lb with scope attached. Recoil is not bad. I am still working on accurization of that one. If it shoots better after that, maybe. I have a 458WM that needs a little brother. In reality it is earmarked for a TX Nilgai hunt next year.
Either way, time to start planning your first Safari. Let me know if I can help? BTW - what part of KY is home for you?