The one thing I don't really enjoy about the Heroes series is that in seemingly every single entry in the series the difficulty curve of a typical match/campaign looks something like flying up a 200 meter wall and then jumping straight off when you get to the top. I can only assume this is because in lieu of developing a competent AI they simply give it production advantages. So once you meet, let alone overcome, the AI's production it's basically game over. And for the same reason the only realistic strategy on higher difficulties is to rush, rush, rush lest you find the AI a month or two into the game with an army a couple of magnitudes larger than anything you could ever produce.
I'm not sure how this could be remedied or even if it's just me that thinks it an issue. Anyhow, anxious to hear more about the game!