i'm sure he does. if i were getting paid what he's probably making (i'd say at least 6 figures), i certainly would. they probably rehearsed for 2 weeks in a stadium or large arena, too.
however, not all of us have that luxury, so we try to do a lot of that on our own without having to rely on the soundman to do it.
Absolutely. I have a DVD of Queen's '86 Wembley concert with rehearsals as a bonus feature. They rehearsed in a large room (possible a warehouse), with full stage equipment inc grand piano, huge drum riser, stacks of AC30s, huge lighting rig. So not only where the band rehearsing live renditions, but the sound guys where rehearsing mixes, the lighting guys where rehearsing sequences, the techs and roadies rehearsing instrument changes and off stage switches etc. Heck, the first night of the concert was also a rehearsal for the film crew, and they recorded the concert proper the second night.
Sure, most of us can't afford to do this, but if you have your own soundman, it really is useful to rehearse once with him before your first gig with them. We've had ours a number of years, but we still have the odd one or two rehearsals a year with him to keep him and us up date with new song and new gear.
Also, you should be used to setting your own volume levels in rehearsals. If you aim for consistency, and you don't have too many extreme changes or volume jumps, it should make live shows much easier on your soundman. Just because a song is more drum and bass focussed or keyboard focused doesn't mean the volume has to be cranked on those instruments. If anything, other instruments should reduce their volume with drums staying more or less level.
Unless drums are miked, it's difficult to change their volume, so use the drums as the constant and mix around them. If the drums are too quiet in a particular song, everyone else turn down! If you can, at least mic the kick and compress it. Then the the drummer can still play dynamically without losing too much volume.