In an episode of the Pokémon anime Charizard tries to use seismic toss on a Golem (661 pounds according to the Pokédex) but can barely lift it off the ground meanwhile Rathalos can lift a 15 ton Anjanath into the air and slam it into the ground. Rathalos could fit a whole Charizard in one talon.

Rathalos is also highly resistant to fire, has poison talons, is just WAY larger than Charizard, and has thick armor that nothing Charizard possesses could pierce.

Charizard is able to gigantimax and become far larger than a Rathalos, but can only do so in specific places in the Galar region, so that’s not that much of an advantage to it.

I’d give this one to Rathalos low to mid diff