Would PLD be viable if its mitigation was as superior to DRK as its DPS is inferior?

[giantslayer]

From what I've seen others post, it seems Paladins are around 10% lower single target DPS than DRK and 20% lower than WAR (AoE is probably a much wider gap). Paladin is supposed to bring increased defensive capabilities in exchange for lower damage. Comparing to WAR is apples and oranges, but DRK is apples to apples as they are very similar.

Compared to DRK, PLD has:
- A physical shield, which people are saying is good for 3-5% on average.
- Shelltron
- 10% higher mitigation in Sentinel than DRK's equivalent (10s with 180s cooldown).
- Hallowed Ground is a lot better than Living Dead (although it is 420s vs 300s cooldown).
- Stoneskin and Clemency, which people don't seem to think highly of (I don't have Clemency yet on PLD myself, so I can't say much for myself).

All-in-all, this doesn't really feel like 10% overall better defensive capabilities than DRK. It feels closer to 5% IMO, less if you put more weight on a magic based scenario like A4S. I wonder if the problem isn't that defensive tank is a useless proposition, but that PLD simply isn't as much better at defense as it is inferior at damage? Most of the discussion has been purely on DPS, not on defensive capabilities.

My question is: If PLD had an across the fight average 10% better defensive capabilities than DRK, would it then be viable in Savage?

Say hypothetically they increased the damage reduction in Shield Oath to 25% (for damage taken, not dealt). Is increasing defensive capabilities a viable alternative to increasing DPS to bring balance? (Note: I am not saying SE should buff Shield Oath, just throwing it out as a hypothetical scenario.)