I'M a bass player (bsicaly) a soundman and I'm also doin ( I don't know the right therm in english) some pre production for a festival as the "technical director". We get acts from all around the world , I'm in it right now.
So I'm the one receiving the "riders" from the band , and checking everything out to see if the demands and the contracts fits the bill , technicaly speaking.
So I'm very well aware of all those things.
A band's rider is always suggestive. They stated ; "We want 105db a the desk , the desk should not be under a balcony ... bla bla , want PA like Meyer , Adamson, Heil , etc... No behringer... bla bla bla"
These are always suggestions.
If you play to a house that has an under balcony board ,the band will have to deal with it. They are not gonna renovate the hall because of that demand......
And the patch I receive , is suggestive too. If the band sends a rider and ask for a B52 on the kick and the place only has a 902 , that's what it's gonna be. Particularly true if thay don't have their soundman.
Very big acts comes with their sound system and sound crew. This does not apply.
In general what I say is; if you want the soundman to use the stuff you want them to use , hire yours.
Or else , deal with it.