Only possible exception to it is "combined arms" fleets
That's a good point, I forgot about those as I don't play those types of fleets, but yes, that's another type of fleet that doesn't need much baby-sitting, all for the same reasons as the others; the AI can't properly deal with those types of fleet formations on the strategic level and the enemy fleet's AI gets overwhelmed, but the player's fleet AI plays it fine.
In my experience, where the AI most noticeably fails at are in flux management and threat assessment/spacing;
Which are all more difficult than they sound.
I realise that and I don't want an AI that can play as well as a human player, that's completely infeasible for an indie dev team creating a game like starsector, and would probably require something like Google's Deep Mind to pull off.
What I want is a reduction in the amount of times I notice the AI doing these kinds of annoying behaviour, or a reduction in the impact/noticeability of the behaviour when it does do it.
Whenever I see the AI derping around like that, it completely breaks my flow/immersion in the game, which is why I think the OP's idea is a good one. Having some kind of more strictly followed commands available to the player would be a good implementation into the game; no more will I see my Eradicator (P) being chased off a capture point by a kite with a light auto cannon and a reaper torpedo, if I could tell it to park on top of the point and not move.
I don't need an AI that can recognise the kite as a minimal threat (maybe even burn drive in and destroy it), but what I do want is an AI that doesn't commit horrendous tactical/strategic blunders constantly. In the current state of the game, these situations are the norm in my battles; if I run around with a fleet of varied speeds and weapon ranges, I can almost always find at least one ship (mine or the enemy's) doing something that raises my blood pressure when I hit tab and look around the battlefield.
Hopefully something can be done to change this type of behaviour from extremely common to uncommon edge-chases, whether it's the implementation of something like OP's idea, or tweaking some of the existing AI priorities/weights, I just want to play a battle from start to finish without constantly witnessing these types of immersion breaking behaviours the AI is so fond of committing.