An optimal moveset for Golem? I don't think so.

It is clear that someone at GamePress owns a legacy Omastar. I can imagine it would be a nice mon to have in your roster. They sing it's praises quite a lot...and perhaps it is valid.
However, when it comes to Golem and his legacy move, he is forgotten. As an owner of Mud Shot/Stone Edge Golem, I can tell you this is clearly the optimal moveset (probably followed by Mud Shot/Eq...but I have no experience of this) - and I prefer to choose my legacy Golem over any Rhydon or Golem when I go into battle.
He rips through Snorlax faster than any Rhydon.

As for RT/SE Golem, the dbl rock moveset - I keep one around for when the first Tyranitar appear although there will be better matchups, this is an easy one to keep until it can be replaced.

In short...legacy Golem is a better moveset than any current moveset.

I think the only moveset that Golem is useful with is Rock Throw Stone Edge. This is almost specifically tailored against charizard and lapras.

(it is a YOLO choice against lapras since Golem is weak to ice but at least it takes down lapras with speed, something not many pokemon can claim)

For attacking, Golem's optimal moveset is generally considered to be Mud Shot + Earthquake (legacy moveset). Golem with that moveset is the best ground Pokemon attacker in the game based on DPS (according to reputable sources like Trainer Tips). It's even better than Rhydon with Mud Slap + Earthquake, which is now the best ground Pokemon attacker currently available in the game. Mud Shot + Earthquake is also two moves of the same type, which is generally preferred for attacking.

Mud Shot + Stone Edge (legacy moveset) is a close second. It yields almost the same DPS, but Stone Edge has a slightly faster cooldown than Earthquake, which gives you a little more time to dodge.

As someone with both legacy movesets, I prefer Mud Shot + Earthquake. Stone Edge has a slightly faster cooldown, but I don't feel it makes that much of a difference in actual battles and Earthquake packs a harder punch.

Technically, the best attacking movesets Golem can currently obtain are Mud Slap + Earthquake followed by Mud Slap + Stone Edge, but Rhydon can also learn both of those movesets. So you'd be better off with a Rhydon if you want to use either of those movesets.

With that said, if you don't have either of the legacy movesets I mentioned, the best attacking moveset (that's currently obtainable) to have on Golem is Rock Throw + Stone Edge. Golem with that moveset is the best rock Pokemon attacker in the game based on DPS. It's the only moveset currently available to Golem that makes it more useful than Rhydon.