I have a problem somewhere. Ratmen, lizardmen, siege, whatever. Ok. I select a few squads and tell them where to station. Then I wait. Nothing happens. Hm, why? I look in units. This little piggie is sleeping, this little piggie is filling a waterskin, this little piggie is eating, this little piggie has decided to pick up some equipment that just became available, and this little piggie went "wee wee wee" all the way home.
Sometimes I'll have a commander who is actually on the ball and ready to go. Half the time, he gets most of the way there and then - "Drink" or "Eat" or "Sleep" or some other nonsense. And those of his squad that are ready follow him, of course.
Where's the Sheriff when you need him? Why can't I slap these mutinous jerks in prison?
Meanwhile the hostiles are partying, and half my civvies are bouncing back and forth between the core area and whatever jobs need doing in the problem area that they keep getting scared off from.
When a squad is on duty, NOTHING should supercede that. When a squad gets put on duty and stationed somewhere, ALL dwarves should WAKE UP and go to the position. Perhaps they fight less effectively because they are tired or hungry or whatever - tough. Orders is orders. They should follow 'em. All that other activity should be allowed ONLY when off duty.
This might cause problems with standard patrol routes and remembering to take squads off duty. There are various ways to handle that, setting up time limits on the duty period and so on. Depends on preference.
As it stands I have just decided that the only effective way of getting a force somewhere is to
1) form a squad and set it on duty,
2) station it somewhere,
3) re-promote all the members of the squad back into their one-dwarf individual squads, so the ones who are ready just GO, and the others can screw around with whatever it is they think is more important than the greater good of Dwarfness.