My theory of why Shanks is half the man he used to

So we all know that Shanks and Mihawk fightes were some next level stuff and after Shanks lost his arm Mihawk refused to fight.

Now my theory is that it isn't about the arm at all, it's about not fighting.

Hear me out, Shanks got The nika df, and that was in possession of wg(who's who to be exact), but even that time he didn't directly engage in a fight with him, he stole it and left. Similarly, why would oda first show that Luffy is willing to sacrifice everything to be a pirate but then immediately after show that even as such a strong pirate shanks won't fight a cheap bandit. And it's only after that Luffy gets the df and then the strawhat (parallels with Pirate king)

So what do I mean by all this, some fights ain't worth fighting. Maybe fighting with the holy knights isn't worth it afterall, it's useless. And I believe brook made the mistake of fighting then head on and got killed, with that mysterious illness and poison.

One more point to wonder is in Jaya, Luffy refused to fight, and it was only then we get to meet the true Blackbeard (there's a possibility oda night be hinting that he isn't worth fighting too)

About why Mihawk wouldn't fight- Because he ran from a fight, and the pirate spirit isn't about cowardice, so it isn't the physical hand that makes him half, it's the mental one