Maushold really hoping to see a Gravity-setting ability for Accuracy and insuring Spikes damage.
Real talk though I think on the Wide Lens set, you really want to go all in on Tidy Up + Population Bomb, with your remaining moves strictly focused on things that move can't hit already. With the 9 average hits after accuracy, you're looking at a 270 BP STAB move (so 405 BP effective) that goes around Substitutes, which is essentially only going to lose in damage to Immunities or a Quad resist (202.5 BP vs a 2x Technician Bite being 180 BP). I see Trailblaze and Bullet Seed mentioned in the OP set for Bulky Waters and Grounds, but as mentioned those probably won't hit harder than Population Bomb on any case relevant to OU (5-hit Bullet Seed is 187.5 BP x 2 = 375, somehow still below neutral 9-hit Population Bomb).
At that point it feels like you either need coverage to hit specifically things that don't care about Population Bomb like Ghosts or certain Steel-Dual types, Barb/Helmet Targets, or a move to enable easier set-up for Population Bomb (Encore or Taunt to get more chances to grab the Tidy Up Boost for example).
While less extreme it reminds me of Dracovish: Moves that aren't Fisheous Rend were only run for things Fisheous Rend literally could not touch because the BP disparity was that absurd.
This was what i was thinking. Bite is needed for sure to deal with ghosts. Beat up is too unreliable i feel especially after 1 or 2 of your pokemon are fainted. I am thinking superfang may be your best option as a 4th move. Trailblaze will probably be best if you really need something against rock types, as since vs bulky waters unless its a 4x weakness population bomb is still better. And i think super fang would do just as much if not more damage vs most rock types at full health, and then you can probably population bomb them from their to kill them or get close, or use bite.