@grey matter who you think quillingham and sommers are fighting?
With Loki playing a similar role of Law (strong ally)
Quill guy (Caesar) gets beaten by Luffy; Sommers (Vergo?) gets beaten by Loki or Zoro, may have some clash with Sanji; Gunko (Monet) gets beaten by Robin or Zoro (aura diff'd).
All of them, bar Sommers, get destroyed. Somers puts up a good fight like Vergo did.
Of course, Shamrock can come back again, and all of this changes.
Luffy has never fought a swordsman in a major fight, and I don't think Oda will be keen on drawing a swordsman slashing Luffy a ton of times. Zoro fits stylistically, but he obviously won't get the full 1v1 fight cause he never fights the strongest opponent - I can see Zoro and Shamrock having some clashes, but Loki ultimately taking over and being the one to chase off Shamrock (don't think he gets defeated here for good).