I imagine there's plenty to be said on this topic, so here's just one specific point to start with: * Shamans should check their allies' HP and armour cards before casting Unholy Frenzy (et al.) so as to not instantly kill them.
A flying monkey Ducked my Cone Of Cold then played it, hitting 2 of my units and all but 2 of the enemy units (including reducing one enemy unit to low enough health that he died from a burning debuff he already had. A monkey was sitting on a VP, I attacked him and triggered his Acrobatic Flip, He moved himself off the VP and moved me closer to the VP. I think an AI pushed me onto a VP once as well.
* The AI should not 'fake-out' pass (ie. pass before using most of its cards) when the player is in control of the victory location and will instantly win by ending the turn. There are probably other flaws along this line - the AI really needs more 'common sense' checks before performing risky actions.
A general check on every AOE attack would be nice "Taking into account revealed armours/blocks, will this do more damage to my team or my enemy"
On most modules, I think it's fine that the AI makes mistakes. I presume there's some element of the game master 'role playing' as a not-necessarily-tactically-wise monster... But for the ranked PvP battles against AI I think they should take a bit more care not to make obvious mistakes - such as attacking a character protected by Impenetrable Nimbus, or wasting move cards and step attacks which are completely negated by encumbrance (although I still sometimes do that myself...)
I just thought it fit the flavor A slightly mad shaman who doesn't care about its dumb allies enough to be careful. "Bah, the fool was too weak to handle the POWER..." But yeah, the AI doesn't handle VP squares very well. Another problem I've often seen is that an enemy will use Dodge, move to another square that is still next to the attacker and as a result still get hit.
* Whichever routine the AI uses for deciding on a target square to move into should be called and considered BEFORE they decide whether or not to use a movement card at all - as it is, I just watched a marksman waste three movement cards in three consecutive turns without even changing its facing.
The AI should check for hostile terrain before moving to escape from hostile terrain. I have often tricked the AI into moving from acid into fire and similar, because it only wants to escape the current hostile terrain and does not consider how it is going to get out of where it is going.
I once saw a geomancer, after his Hover wore off, move onto lava and then stay there with move cards visible in his hand.
