It is doubtful Keith was considering jacketed hunting hollowpoints, and if we're talking about wound track size, then it would be well worthwhile to consider. The beartoothbullets article you linked makes an argument that extreme penetration is not useful on medium-sized game like deer and antelope, but if wound track size is meaningful, then hollowpoints are also, particularly deeper penetrating hunting hollowpoints like the A-frames, Partitions, or Barnes XPB (not talking about LE/self-defense loads here).
The data in the article indicates that a larger caliber will produce a larger wound track for a given velocity and can produce the same size wound track at lower velocities than a smaller caliber, just as you wrote. The article makes the point of not using more cartridge than is really needed to avoid suffering unnecessary recoil, noise, and wear. But considering expanding projectiles, we can easily get .50" diameter from a .357 and a wound track size at least as large as a 50 caliber that is not expanding or at a very high velocity. While the hollowpoint will require higher velocity, and the smaller caliber will require higher pressure, powder consumption and recoil energy will still be lower. By the article's chart, none of the other cartridges had less than half the recoil energy of the .357, but none of the RPI's were significantly higher until recoil energy was 3, 4, 5 times higher.
So if I understand right, the big bores can probably be justified with hard cast bullet penetration depth and wound channel size on big game like brown bear, moose, elk, bison, but for medium-sized game like deer, black bear and antelope where a .357 can achieve good penetration with the kind of expanding bullets I mentioned, it seems the big bores with non-expanding bullets can claim neither greater wound track size nor meaningfully greater penetration. What they can claim is lower velocity and lower pressure, but not lower recoil energy. Feel free to argue my points because I'm not claiming authority.
I'm no expert either, I have just read a lot on THR and in a variety of articles and books from some very experienced and astute individuals. I think you and I agree on the article, which concerns the right caliber and speed for game. I would take a fast .357 over a cowboy loaded 45 Colt for pronghorn on the prairie, not so much because I need the power (either will do) but because I need the range. I could use either one to hunt game up to deer size, and I would feel comfortable with either. One point that I have learned from other members of this board is that speed offers a second advantage at long range as there is less bullet drop.
Regarding speed and recoil, I have played with high velocity 158 grain .357 loads in a 5.5 inch Ruger Redhawk and at a certain point, I have to spend more money on bullets, as I need jacketed or gas checked bullets to prevent leading. I will say this, even out of the Redhawk, 1550 fps 158 grain bullets begin to hurt, and I have to change my grips out for Pachmayr Presentations that offer padding but don't fit my hand as well at that speed. I have also shot hot high speed 180's (not chronographed) from it, and it's fun but also uncomfortable on my hand. I never realized how underarmed with a .357 I was until I was within 20 yards of a moose and thought to myself "I want to have a larger caliber." In addition, the Redhawk weighs in the 55 ounce range, and while I do carry it, I prefer the weight and recoil of a Blackhawk in .45 Colt with a 255 grain at around 1000 FPS for bumming around woods where the longest range may be 50 yards.
I also agree with your thinking regarding modern hollowpoints, which is why LE agencies are again going back to 9 vs. 40 and 45. Modern hollowpoints are getting more reliable in expansion, even as they penetrate difficult obstacles that have clogged vintage hollowpoints. The hollowpointed bullet at 9-1100 fps is the right bullet for the right purpose: protecting society from a bad guy without over penetrating him, while taking in consideration barriers such as glass, wood, sheet rock, etc.
Regarding hunting, Keith did not have access to modern hollowpoints, but I believe that he would argue that 2 holes in game are better than one, as there is space for bleed-out. I believe that the appropriately hardened cast bullet of a Keith style, or an LBT bullet will always cause the wound diameter without the need for expansion, and can cut through bone better than a hollowpoint.
It's a matter of choosing the right bullet, the right velocity, and the right caliber for the game. If I lived in my beloved South again, a .357 would be all I need for hunting and self-defense. I don't, and outside of the urban areas of the West, prefer a heavy cast bullet at a modest speed in a .45 caliber. If I lived in Alaska or the mountains of Montana or Idaho, I would look into the .480 Ruger, or the .475 or .500 Linebaugh. It's simply a measure of the best all around effectiveness for self defense and hunting.