Great article! There are a few things I would like to point out, though.
3 Pokemon Reversal is good, but I would really like to see a 4th. Dragging up a Garchomp C to KO it with a Belted Earthquake is important in the LuxChomp matchup, so I feel a 4th Reversal is needed. However, LuxChomp can find it difficult to deal with a Belted Heavy Impacting Donphan, and this list looks like it could get a 3-Energy Donphan up really fast.
ERL is a great tech, as you already know. If you are facing Cursegar, you can easily take down pretty much the entire deck by using two Thunder Falls. ERL can also suddenly win a LuxChomp match (or give you a big lead) by taking down 2 Crobats, an Uxie, and another Uxie or Azelf.
Speaking of Cursegar, I found that my Donphan/ERL deck smashed it to bits. I found it was pretty much an autowin, and I steamrolled every Cursegar I faced. I don't know how easy it is to get a T1 Donphan under a Spiritomb lock with this list, but I still think that you would crush Cursegar. Also, Donphans are pretty much uneffected by Compound Pain since they receive 0 damage from each other's Earthquakes, and if they do have damage on them, Compound Pain would only do 10 damage to them.
Otherwise, a great article!