In the "d" menu, if you use the "Set Priority" control, you can very greatly influence the dwarves' behavior. It defaults to "4", with "1" pretty much telling them to get their butts in gear and get it done now, and "7" telling them to do the job whenever they don't have anything else to do.
Are you sure about that? I always thought that mining priority only determines which tile he goes to once he has chosen to mine, and not whether he chooses mining over some other activity. But I've never tested it.
It's not "absolute control" of course, but it seems to work in general that way for me. There are times when extra measures are needed, like turning off other labors. One in particular is my only woodcutter. We do the tree felling in batches, just occasionally, and even on priority "1" I might need to turn off other labors. If I had 5 woodcutters it wouldn't be a problem.
If I have 8 miners for instance, it's never a problem to get at least 2 on a new mining job. And in this case I also see that high-priority (low number) will bring more miners quickly to a newly designated large mining area than if it was low-priority. Especially a dozen separate newly-designated "automine" tiles.
Actually, I'm very happy that we can not control the dwarves' lives and work as exactingly as we would like. That would be too easy and the dorfs would seem to be nothing more than robots, taking away from the draw of this incredible game. The challenge of finding ways to bend them to my will can be engrossing. But of course, when their stubbornness results in mass death because a lever TO STOP THE HORDES FROM GETTING IN wasn't pulled... that's another story.
Basically, I've found that having many dwarves assigned to each labor makes things get done fairly efficiently (at the expense of higher skill levels, but that's no big deal for me except in specific instances).
But having rambled on... no, testing things isn't my style so it's all just observations.