I see O'Conner as the world class hunter. He had, or at least developed, the resources to travel the world and amass far greater experience on a broader range of game than many others who were equally opinionated. I see Elmer as the frontiersman, and despite having travelled to Africa, O'Conner was more worldly. Elmer grew up with a sixgun in hand, and a rifle usually within easy reach. I don't expect O'Conner did near as much shooting, and he mostly stuck with cartridges smaller than the .30/06. I'm not sure he was as gun knowledgeable as my childhood hero Warren Page, and neither was he as gunny as Elmer. My perception is that O'Conner lived to hunt rather than for the tools of the trade, despite the fact that he appreciated a good rifle. If Elmer said something worked he had personally seen it work, and if he thought poorly of it, he had personally seen it fail.
Both men were influenced at an early age by the rifles that ended up defining them. O'Conner was perhaps overly impressed by what is arguably a nice deer rife cartridge, although it appears that he had a high regard for the .30/06, while Elmer was equally impressed by medium and large bores. A .338 on pronghorn seems a little excessive, but it worked, and I have shot game of similar size with a .375. He seldom had much good to say about rifles of .30 caliber or smaller on big game, but if I recall, he considered his .222 Sako the most accurate rifle in his vast collection. The views of both men are valid to a point, and both views are flawed to a point. Neither liked to have those flaws pointed out, which may account for the animosity between them. Despite that, both were likable in print and a pleasure to read. Having said that, the editors at G&A said Elmer's stuff was written so poorly it was difficult to tweak into readable language. O'Conner wrote very well.
Who am I more like? I fall somewhere in between I suppose. I think powerful rifles can be more versatile than high velocity small bores, but if I had to choose a single cartridge for the rest of my shooting life it would be a .30/06. But I like heavy bullets, with enough velocity to flatten trajectory, produce large wound cavities, and preferably exit a game animal. When I carry a handgun for protection, I want a normal sized gun in a big caliber that fires a heavy bullet, but not so much recoil as to prevent a fast follow up shot. Elmer thought poorly of the '06 and O'Conner wasn't much of a handgun man.