Our opinion was to leave everything unchanged. But I've already imagined what it would be like if nothing had changed since the times of Heroes 1x, not even since King's Bounty!

There are things that cannot be changed. For example, the interface. Even now, new fans of Heroes will not be able to play parts 1-4. The gap is enormous. I don't think I need to explain why;)
I'll add my own thoughts. Playing 5 is very difficult for me. If the Warcraft interface isn't hard to master, then the appalling minimap and MOST IMPORTANTLY - THE ABSENCE OF THE "KINGDOM OVERVIEW" BUTTON - is simply anti-humanism. Without this button, I cannot imagine a Heroes game:(
As a continuation of the series, Heroes 5 is a failure. As a standalone game - it's actually quite decent. (not imho)