Thanks a bunch for the input so far, all of you.
The way the AI works and acts surely has a deep impact on the game and how enjoyable it will be to play it in the end, and therefore is a very intresting topic to talk about.
Without taking into consideration how hard it would be to implement it into the game, I want to point out a few things which should be kept in mind when tinkering with the battle behaviour of the opponents. I have a lot of trust in the capabilities of our beloved developers, but still. Cannot hurt to mention it.
At the moment and from my personal point of view, the enemies mostly use abilities which come with the weapon of choice – split shield, stun, riposte, shield bash and shield wall. However, they seem to use these rather randomly. The rare exception is the rotation perk (level two in the defense tree), which I personally never saw in use so far – but in BumpyMcSquigums’ let’s play on Youtube I could see two bandits swapping their position twice by using that perk, so they ended up in the very same position as beforehand. I’ll try to look up the exact part when I am home, and link it as a reference.
If we are going to improve this however, we should take a close look at who and how far. The orcs for example excel by being absolute killing machines in a duel, which is a good reason not to take them on alone, or at low levels at all. Which is totally fine.
But giving an enemy a broader skillset and a better AI to use these, could also be utilized as a way to set apart the different factions from each other. So while orcs would rely not much on any weapon abilities or perks which require finesse (like riposte), it seems totally fitting for them to use shieldbash and other actions which rely rather on strength. I would not expect any of them to have a great sense of positioning, though. Goblins, on the other hand, are a totally different matter.
So all in all, I would encourage to give the enemies more access to the perks besides the normal weapon abilities, but make it strongly dependant on the faction – and even within the faction. If bandit thugs were using their skills in the same, smart way as bandit leaders, it would not only make the game probably a bit too difficult without the ability to tune it further for less skilled players, and also waste some potential which could otherwise be used to differentiate the particular types of enemies within the same faction.
I wholeheartedly agree to the idea to back the necromancer up with a guard. It is not only very fitting, but will also make him much more useful. Just yesterday, I engaged a group of undead in a hideout; two normal skeletons, two skeletons with hookbills, eight fallen heroes and one necromancer. It was labeled as ‘deadly’, so I was very careful about my positioning and movements during the fight. The necromancer however, did absolutely nothing in this fight. He kept lurking way too far from the frontlines to be able to resurrect any of his minions, so it never happened. Then he took a hit from an arrow because he was the only really useful target for my archers – and then fled when enough of the fallen heroes were down to send a shieldbearer after him. An undead guard who could shield him from the arrows and make him a bit harder to catch would be awesome.
Horray for lots of text! It was quite nice to read.
In most of your described cases I would agree, in particular to your last sentence: If it is not broken, do not fix it.
But in a few cases I have made a different experience. For the enemy archers, they quite reliably aim for my un-shielded troops. The only times where I see them shooting at shieldbearers is, when they do not have any other valid targets. What I am more concerned about with them, is when they try to shoot and when they try to move. The positioning seems to be very difficult for them, especially in forest battles. It has happened a few times already to me, that I had to scout the map after the battle for that one last archer in the forest, who was confident sitting where he was and not participating in the fight at all.
The other point is the defensive AI tactic. I agree to the behaviour which you described above, where the AI tends to move onto a hill and camp there if necessary, so they keep the advantage of the high ground. However, if you move all your troops out of sight from them, they will come and look for you. In most cases, only with a few of their men, so they split their forces.
If nobody pointed it out by now (took a while to write this all up at work), bushes work just fine to conceal your units. However, if the enemy saw you moving into it, they will remember your unit being there for a while. So not only your battle brother has to be hidden to make this work, but also his movement into that cover. Therefore, they really work best as am-bushes (sorry for the pun). Fall back, retreat some guys into bushes, the rest further. The enemy will come to them, even with his archers.
Focus and teamwork: This is one of the biggest advantages I currently have over my oponents, and which allows me to beat much tougher enemies if I can prolong the start of the fight until I have reached a forest. Therefore, out of very personal, selfish reasons, I like the fact that I am able to separate the opposition well there and would like to keep it at that. However, I can understand that others might want a smarter behaviour, a bit more of a challenge in this regard, and improve their behaviour. Causing the AI to stick together more closely in confined circumstances like forest battles will surely help them a fair bit. And I think I have already seen some group tactics, as they already spread out in open fields before they engage to make it more difficult for your archers to hit them with a lucky fluke, should they miss their intentional target.
Plague Rats - we're not famous, but we get the job done.