I don't know if I'd trust a 260 JHP at that speed. 850 is real marginal for a JHP to expand, you need a pretty decent cavity and the heavier the slug is, the harder it is to put a good enough cavity size on it.
Now, maybe they got it right, I dunno. But at those speeds, I'd put more trust in a "flying ashtray" of some sort. Nobody else is loading a defensive JHP 260 at those speeds or any other that I'm aware of, so there's no "track record".
Proload decided they had a 45ACP recipe sorted out, so they just straight cloned that. That makes sense. The Winchester Silvertip has been a known quantity for a long time. Cool. Ditto the Cor-Bon.
Call me conservative, but JHPs can fail to expand for up to three different reasons: too slow, too fast, or they clog. Go with what you KNOW works because if the excrement impacts the rotary air movement device, that extra little bit of confidence you get out of using "known quantity" ammo and a good gun can translate right to your facial expression and body language...and raises your odds a Goblin will run and you won't have to shoot at all. (Not the only factors of course, training is the MOST important...but "gear trust" matters too.)