You will do fine with the TSX on your safari. They are great bullets.
My main point was that bullet performance is more complex than the simple theory of extra weight retention makes it sound.
Some weight loss usually results in a bigger wound channel INITIALLY, on the side of the animal the bullet enters. This results in a bigger hole in at least the near lung, and maybe the far lung, even if the bullet does eventually end up with a smaller frontal diameter. And a bigger wound channel in vital organs is what kills, not hematoma.
I have also seen TSX's (and bullets like them) open up to more than twice the original diameter, but in general they don't create the tissue destruction of bullets that open up wider, or even lose some weight. This is on average. There are always exceptions to average peformance with any bullet.
But I have seen bonded-core bullets open up to three or even more times their original diameter. It depends on the deign of the bonded-core bullet. Again, a lot of people like to make up "rules," such as bonded-core bullets open up to 3 times original diameter (or extra weight retention means more penetration). There is a wide variety of frontal area between a typical expanded North Fork, Trophy Bonded and Woodleigh, for instance.
You are mistaking one phenomenon with what might be called "pre-premium" bullets (the failure to even penetrate any vital organs) with what wider-opening or partial-loss premium bullets do. I have yet to see a Woodleigh, for instance, fail to penetrate the vitals of a big game animal no matter how widely it opened--and they will indeed make a bigger hole than any bullet that doesn't open up that widely. This is assuming, of course, a reasonable match between bullet, cartridge and game.
My final point is one that I've made before: If penetration was the entire "secret" to bullet performance, we'd all be using solids, even on whitetail does.
