I always have two Canon EOS 5D Mark IV bodies, with two different lenses on them: my Canon EF 24-70mm f/2.8L, and also my Canon EF 70-200mm f/2.8L.
When I’m in the pit and want to capture some details, like a hand on a guitar or something like that, I like to have my 70-200mm so that I can really zoom in and get a really crisp close-up.
Sometimes you want to shoot the little emotions of the performer, really cropped in from close by, so I’m basically always jiggling between the two cameras.
My brain is set up like that: I know my 24-70mm is there and my 70-200mm is there, and I don’t even think about it any more.
During the show I switch off; I don’t really do it consciously, it’s just instinct. A very long time ago I started out with two lenses and one body but had to constantly change and miss parts of the show. So if you really want to cover the whole show, then it’s advisable to have two bodies with two different lenses.