Interesting. First Thorax episode two eps ago and this one has a similar approach: Mess things up and that fixes the problem. Actually not that rare, actually, if you think about it. Starlight and Trixie themselves weren't the friendship problem this time as severely as Spike. But it was close. But more or less many episodes follow this pattern. When does the first attempt at solving the problem ever succeed? Exceptions from that are a delight to me. Magical Mystery Cure comes to mind. I am so glad they didn't have more time to drag that out.
Pretty early it was obvious to me the way to help Pharynx was to give him purpose again. There's a reason he was the only one preserving the old way. A pendulum that swung to the other side needed to come to the middle. No one left behind, so to speak.
Beautiful role reversal writing: Thorax used to be in a very similar situation as Pharynx was now.
Also, in how in the end Pharynx transformed, this episode expressed a very profound spiritual lesson: From acceptance comes change.
P.S.: I'll never get used to ponies walking on three legs while talking with their hoof. The animators should really focus on making them more expressive in other ways if they feel it necessary. It's mindbuck to me every time. Something I'd expect to see in a YTP video and laugh.
P.P.S.: Maulwurf - German word for mole. Nice easy pun for a mauling menace.