>>36254052non-STAB moves from 60 Special Attack don't count as coverage. All the TMs I mentioned are available in game and conveniently just before any major boss fight where you'd need them (FE you find the Shadow Ball TM just before Mimikyu).
>I find the stronger core water type movesSparkling Aria has the same power as Aqua Tail without the chance to miss, and Primarina learns it one level earlier. Before that, Gyarados has to rely on a much weaker Scald.
I agree that Dragon Dance is Gyarados' objective advantage, but it doesn't get it until level 45 and you could argue X items make Dragon Dance less valuable. In USUM you can even get Choice Specs and pretty much sweep everything with Primarina without setting up (Primarina is slow but so is the rest of the region).
