The relocating experience thing means nothing. Fisher, of course, blew it up big because that's him; he has little other positive achievement to fall back on.
Besides: it wasn't Fisher who organized the relocation. That is entirely a FO plan created by hiring logistics people and companies to make it as smooth as possible.
Relocating is a normal and usual thing in the business world. It's not that different for a football team. And whatever difference there is revolves around the local marketing of the team, of which the coach plays just a small role by making public appearances.
If one wants to give Fisher some credit for "relocating" the Rams, then certainly he gets the credit for a 4 win year following relocation. So he failed miserably at Relocating 101.
I do think it is fair, though, to say that it is not the same thing to move a team from St. Louis to LA as it is from Oakland to Las Vegas. You're not dealing with wholly different cultures. I think it's probably reasonable to say that Vegas has derived most of its current vibe and culture from California since it is populated heavily with former Californians. Heck, the players that love California won't even move. They'll just get a short term apartment rental to be in Vegas for team functions during the season. It's not even an hour flight to get from Vegas to Oakland. You can drive it in a morning or afternoon.
So for Gruden, it just means he won't be house hunting in Oakland; he'll be renting. Otherwise, it'll be business as usual for him.