Баги "Might and Magic: Heroes VI"

I discovered a very interesting bug today. It’s unusual, but it doesn’t hinder the walkthrough; quite the opposite, it actually helps. Here’s the gist: In the Sanctuary campaign, mission 2. At the beginning of the week, I’m trying to upgrade the priestesses in the second castle. At first, there was simply no upgrade arrow, even though I had built the building. I moved the priestesses to a different slot, and a new (upgradeable) unit appeared in the same quantity! With subsequent moves of the original unit, more and more new units appeared. And the original unit remained unchanged. Here are the screenshots: It seems like some kind of Ubisoft blessing has descended upon me, in the form of an infinite army. It’s a shame that upgrades require money.