This Diglett set is unique as instead of the common physical attacking sets, this set runs all special attacks.
This isn't useful, since it's literally just stating what's listed out in the set. It'd be like having a sentence that says "This set runs Earth Power." - it doesn't give any useful information or provide a hook, it's almost pure filler. Replace with something like "Despite its worse Special Attack stat, Diglett can run an effective special attacking set to trap specific Pokemon that the more common physical variants cannot."
The order of move discussion should be reframed so that Sludge Bomb is the first move discussed. This is an anti-Grookey set, Sludge Bomb is the anti-Grookey move, in the absence of Grookey you would not run this set pretty much ever. This also means that you can mention Earth Power not being weakened by Grassy Terrain without confusing readers.
Basically - explain that this set is used entirely to trap Grookey (since Trapinch can be shut down by Protect Grookey), go through the moves that let it trap Grookey (Sludge Bomb and Protect), then explain the moves that aren't used for the Grookey trap (Earth Power and Final Gambit).
Final Gambit allows Diglett to not be useless in the non-Grookey matchup, as it can Final Gambit on Pokemon such as Ferroseed and Staryu to allow a Pokemon checked by them, such as Porygon or Ponyta, to come in.
Nah, explain that Final Gambit allows Diglett to trap slightly weakened Pokemon that still lacks the power to otherwise KO through guaranteed damage, opening holes for a teammate like Porygon. The way this is currently phrased makes it sound like Final Gambit is being used as a pivot move to bring Porygon in on Staryu and Ponyta in on Ferroseed (or the opposite, but that's clearly wrong), and while you probably could use Final Gambit that way, it's not nearly as useful as a scalpel KO tool.
Protect helps to trap Grookey, as it can Protect to restore its HP if hazards are up thanks to the Grassy Terrain Grookey sets up.
Not hazards, Stealth Rock. If literally any other form of hazard is up, Protect isn't going to consistently save Diglett so there's no reason to be vague.
Not stamping this yet because I'm basically asking you to rewrite it, tag me when you're done and I'll take another look.