I feel the pain of OP since the first death for me was when i met a troll. Took cover from having trees on both sides of me but the bastard knocked both them and me down in one good swing but..
Been hunting for surtling cores and using mace. Can't see this implemented as my swings would be stopped every time by the corridor walls. Would be great to know if the damage is halved, or maybe even count how many obstacles there is in the way of the swing and use that as a divider but to bluntly stop the swing is not something i would be waiting for.
I get the idea, it would be nice to have walls, rocks and other destructables actually protect you but where does it end? I mean, should the attacker get stunned for hitting something that can't be damaged or should only structures have this "impenetrable" element to them and the first wall would take the brunt of the swing, what would the animation be like?
I think it's fair that both my and enemies swings can pass through objects but that's just me.

Thinking this damage divider is already implemented as you can chop down multiple trees at the same time.