"Heroes 5". But are they really "Heroes"?

How did Sandro end up in Ashan if, in the fourth game, he was in Axoth? Can he freely move between worlds, and is he the only one who can? And all he brought to the people of Ashan is his cloak and the name Crag Hack (which Isabel mentions) – is that a logical connection? The developers clearly took shortcuts. And this doesn't do them any credit.