Caretakers are on patrol, I think that's all there is to the AI. So caretakers will get 'stuck' in a task, by looking for the closest thing act upon and acting upon it until it is done, rinse and repeat.
A caretaker built near a factory given no orders from me isn't 'assisting' the factory, it's 'patroling.' Factorys have a small gap in time after building a unit before placing a nanoframe for the next unit. So if there is a large reclaim field by your fac, or a group of low HP heavies nearby, and you are building cheep raiders from your factory, your army of caretakers will spend 65 metal on a glaive, then start reclaiming wrecks in that tiny gap of time, and they will not stop reclaiming the chosen wreck until it is drained dry. If a commander died near your factory, this is painfully noticeable, as there's like a 400m wreck shard, as well as multiple raider/module components, and if you're building <75m units your caretakers have a chance to start excising some of that reclaim without player input, which is unfortunate because the general approach to caretakers is automated/no player input increase to factory buildpower.
Some people have made caretaker automation widgets, but I don't know anything about them. And a poorly written widget may act in a way you would not intend, because of bugs or oversight issues, but if they've written a widget it's probably sensible.