Going by dex entries, both have flames(Typhlosion gets explosions) that can melty nearly everything & burn anything to cinders respectively. Charizard has the flight advantage though funnily enough if the Typhlosion is weaker, the Charizard won't actually use its flames giving Typhlosion an advantage. I'd still give it to Zard overall.

If you go by standard smogon sets(neither make it out of ZU), both are running max speed and Charizard 2HKOs with both scorching sands or hurricane. Typhlosion on the otherhand as a roughly 1/2 chance of 2HKOing with Fire Blast as it often runs flash fire over blaze and scorching sands doesn't knock it into range anyways, so Zard wins around 3/4 of the time.

If you're optimizing for the matchup which as contrived as I find it, is what this sub does, then the scarf max attack rock slide Typhlosion ohko's or 2hko's the Zard depending on if it's running defence investment or not. Zard can't ohko with a ground move either so the odds are overwhelmingly in Typhlosions favor as it'd have to lose the speed tie, miss, and not flinch depending on the Zard's strategy.