I have previously suggested that the AI should be given "standard class path" picks so that it makes better use of its heroes. For whatever reason this wasn't done in 1.2 and 1.3. I don't really know why, it seemed like a fairly easy win to me, but maybe it's more complicated that it looks. Possibly the framework doesn't exist, so Stardock would have to go away and write it? I think it would be worthwhile for them to do so though, especially if the "standard paths" could be modded. AI heroes would be much more dangerous if their picks were made with a goal in mind as opposed to picking the next option available. They sort of get away with it on higher difficulties because they get so many levels and bonus traits, but there's definitely room for improvement.