Rhydon. But why for godsake.

High cp.

And I quote: "Finally, although the objective of GamePress’s very first tier list was to create a defender tier list independent of CP (which is by no means an accurate indicator of defender quality), it is clear that CP influences a player’s choice of defender now more than ever. One big reason is the advent of Blissey, the single best defender to have ever graced Pokemon GO. The ability to place above Blissey (and to a lesser extent, Snorlax) indirectly increases a defender’s value by forcing an attacker to fight the Blissey first."

For the Rhydon vs snorlax logic there's only this one reason: For the Snorlax matchup, one can definitely argue that Machamp is the better pokemon to take to fight snorlax. However, this is hampered by the fact that a good snorlax has zen headbutt which goes super effective into machamp. Essentially this nullifies the 'super effective' that machamp does to snorlax, making for a super effective suicide quick battle.

Rhydon at the very least, resists Hyper Beam. However, with the legacy body slam gone, and heavy slam/earthquake doing super effective to rhydon, chances are rhydon is actually a poor choice now that I think about it. It is also very unwise to not dodge a hyper beam, so the 'I can beat snorlax without dodging'....doesn't really matter.

Provided that the snorlax in question has ZH, Body Slam or HB, then rhydon is a good matchup indeed (though in the anime, snorlax sent rhydon flying in space with an ice punch).

However, I agree wholeheartedly that other than this very restricted scenario, Rhydon is an utterly hopeless pokemon to use if you have a dragonite/tyranitar, or dare I say it, even a gyarados can do better against the snorlax matchup.

I cant speak on how quickly the new fighting moves work, but before the last rebalance Rhydon was the only pokemon that could tank Snorlax. If you don't dodge at all, Rhydon was the best option. I preferred Machamp, but zh was real punishing against him which made high Snorlax difficult. Rhydon being a good attacker against Snorlax uses the same logic as Blissey being an elite attacker...they are because of their bulk.

You also have to keep in mind not everyone dodges quick moves.

Mudslup is a punishing quick move on defense if you don't dodge.

You have to understand Pokemon go is a game of tradeoffs. Dodging Mudslap saves you potions, but costs you time. Rankings try to balance the idea of dodging players and non-dodging players.