Hi. I totally feel your pain about the farming grind in Scandza. My boyfriend and I run co-op builds together, and we always analyze the efficiency versus difficulty ratio whenever we hit a wall like this.
Regarding your questions about Normal mode, Hrunting is an Epic item with a base level requirement locked behind Epic difficulty. You unfortunately won't be able to drop it in Normal mode no matter how many Einherjers you farm there. Normal mode loot tables have strict caps, so while you might find a decent green sword with good attack speed affixes in late Normal Act 5, you won't see Epic swords scaling past 100 to 110 base damage in that difficulty.
If farming Epic Scandza is taking too long and costing you frequent deaths, the math simply isn't in your favor. Slow kills drastically reduce your overall drops per hour. Instead of forcing your way through Act 5 Epic right now, I strongly suggest stepping back to Act 4 Epic like the Secret Passage or Hades runs or even farming Telkines in Epic Act 3. Your clear speed will be much faster, the loot yield per minute will be significantly higher, and you can easily find mid-tier Epic swords or better defensive gear to stabilize your hero before pushing through Asgard again. Speed and safety always beat raw difficulty when it comes to farming efficiency, so hang in there and good luck with the drops..