because noobs make 4 factories with medium?
But seriously:
If you set your caretakers on low, they stay at low - come what will.
If you set your factory on low priority, your unit will be build with low priority.
But you can adjust a single unit's buil priority much easier than nanos.
This new priority applies to each supporting unit which has medium priority by it's own.
It is much more fustrating that units are per default on roam, enemies pick one of your units with a hammer and that unit(yours) try to attack the attacker(hammer) completely alone.
with roam, guards will even attack enemies if the guarded unit retreats.
Stop position for all guards would be nice.
Stop position for all units will help too.
But as far as I know there is a widget for initial states somewhere in the settings.
Too bad that we can't set the widgets stuff from out of the game.
And that the settings will be lost on some major updates.