Agreed, but you can come up with reasonable estimates. A 100k HP dummy with stats imported from specific bosses would do the job too and is probably easier to code than combat log parses (and 100k is enough to make lucky streaks like getting three Lightning Strikes in 10 swings less relevant).
Still, you can clearly calculate that, assuming an eSOS wielder attacking a typical foe, Ravager set > eClaw set > Eternal Flame > 'classic' Claw set = Frenzied Berserker set (on a non-barb). It's harder to compare these effects to indirect conditional DPS increases such as Destruction, but those comparisons are a lot easier than trying to rank defensive effects.
Oh and my thoughts on the Greatclub of the Scrag:
Base Damage: 6d10
+6
Crit profile: Remains awful
Impact
Anarchic Burst
Icy Burst
Superior Regeneration (5hp per 6 seconds through positive energy)
Red Augment Slot
Still 30 damage per swing behind the eSOS on 0% Fort and 5 damage per swing behind against 50% Fort (~9 against Pit Fiends that are effectively immune to Icy Burst), but at least the weapon would have some use, and would actually be the best weapon against some constructs. Impact allows slash-specced toons to pick it up and wield it effectively from time to time.
Superior Regeneration is just a fun effect. In intense combats, it's like having 5-15 more HP.