Whenever I've watched torcedors, they wet the tobacco just enough to make it pliable so as to facilitate rolling.
Most have an old, nasty coffee can full of water and just flick it on the primings.
It's not a big, wet, sloppy mess. Imagine wetting newspaper just enough so it'll stick to a wall, but not fall apart.
They use as little as possible, but as much as is necessary, I suppose you could say.
If the rollers are shooting for an equal amount of water across the wrapper, filler and binder, I sure didn't notice.
Watch a few cigar rollers on YouTube and see what you think.
That's not as good as in person, but I think you'll be able to form a pretty good opinion of your own.