Personally, I'd rather not see army wide Stubborn as the Dwarf equivalent to Speed of Asuryan or Eternal Hatred. Stubborn is nice, but it only kicks in when you lose a combat. I'd rather see something that makes us more likely to actually win in the first place.

Army wide rerolls to hit, similar to Eternal Hatred, Speed of Asuryan or Primal Fury are the best mechanic that I can see. Dwarves struggle in combat due to the low volume of attacks, which is why you see the GW hordes; it's the only way to create that high volume. We've decided that 2A models, Frenzy and units with AHW are out, and for sound reasons too (Dwarves are slow after all). So the one attack per model that Dwarves do have should be able to hit hard (GW) and accurately (high WS with rerolls). Give it a nice fluff coating and Bob's your uncle .

Add in something that reduces damage (armour modifiers or even a universal +1 AS), price it all accordingly, and you'll have combat Dwarves who'll be able to fight in medium sized units, knowing they'll be effective. Reduce the reliance on shooting, allow our blocks to seperate from the war machines without gifting their VPs and you'll have combat Dwarves who'll come out to play rather than castling.