you can use Delsere or TR for a 2000% dmg boost to EB. and that 20% seems to be another multiplier. so a 2400% multiplier with this and the set alone. Obviously it's interesting (and to me always was) to mix in arcane orbit, especially with the recent buffs and complementary items. But also this needs to be tested... we always need to Keep in mind that we have only 13 + 3 item Slots and 6 active skills 
the damage reduction however is really needed. so we can mess around with either F/R rings or maybe even convention/unity for more toughness (oviously halo in cube and APD either cube or maybe the new shield bracers, too when fitting in some shield skills / passives). Oh well this is already getting to deep into it. but yes, i think this is great not only for EB/Woh builds in general but also for EB being one of the main damage dealers in some specific setup.
1
But....oh well, paragon needs to be revised again anyway. The suggestions for +1-2 mainstat for each plvl beyond 800 is also decent but I would prefer a complete rework which deals with the current plvl problems regarding leaderboards and powercreep.
You don't really customize your character with paragon which is the actual purpose for it. The stats shouldn't capping out and somehow not break the game. I think a system which revolves about diminishing returns would be kinda the best solution.
1 plvl point for increasing mainstat +5 (value can be as high as blizzard wishes, just to keep it simple we stay at +5 mainstat for each increase)
2 additional plvl points for increasing mainstat to +10
3 additional plvl points for increasing mainstat to +15, and so on and so forth... just to give an example.
also blizzard should give people more options to spend points in. 4 for each category is simple not enough and my suggestion would not help much with only 4 for each category.