"The same is true for whole classes of cartridges that are practically indistinguishable - 8 x 60, .318 WR, .338 Win. Mag, .300 Weatherby, etc."

318WR versus 300 Wby ?

I really like the 318WR but I wouldn't put it in the same class as 300 Wby.

Yes, both will kill if the bullet is in the same place,
318WR has the advantage of heavy for calibre bullet that penetrates really well but the 300 Wby, it hits hard.