I tried running this deck and I went against a whole lot of Night March in expanded and Vespiquen in standard. They’re so painful to go against, BUT, I have to say, Jirachi really saved my ass so hard - I had 2 Night March opponents concede after I discarded all of their DCE with Lysandres lol.
Other than that I have to say that I don’t quite get how you’re supposed to run it after turns 3-4 when you get the P-Groudon out. I mean as big and scary as P-Groudon is, most opponents are clever enough to hide behind their non-EX Pokemon while P-Groudon is benched, so a lot of the time you’ll have to settle for a 2 for 2 prize exchange (and as it will generally take you more resources to set up, that’s usually not too faavorable) or be stuck waiting for a Lysandre, or a VS Seeker if you discarded him with Battle Compressor.
Also I didn’t find Focus Sash too useful because while it can prevent disaster, you’re still going 2 for 2 against Vespiquen and Night March. What really made the difference there was Jirachi, being able to stall these decks down to a halt, or occasionally outright crush them as they struggle to do anything to him.
Would anyone happen to have a link to a recent video of this deck being played so I could get a better grasp of the general strategy starting with the mid-game point? All of the videos I’ve found are either too old or feature more exotic lists, like a Maxie’s Groudon.