I guess so slow was a bit much. But at this point in the game having a pokemon that outspeeds a base 91 is pretty likely, and if you don't they aren't too hard to find, unlike when we first face Taka and chatot outspeeds most pokemon.
I've had a lot of success with a super luck absol. Give it a scope lens with night slash and psycho cut, and everything is a crit. With swords dance to boost, it ohkos a lot of pokemon.
Thematically, we shouldn't be able to use waterfall anywhere before agate, but for some reason we can there. You can use dive in the cave in north aventurine woods though. There's some hidden item's to find down there.
If you have any common candies you could overlevel your combusken so it evolves then lower it so it obeys. The extra strength may be enough to take down the chatot, especially if you outspeed from speed boost.
That means that the are in which you caught it was removed from the game. A couple parts of the early game have been changed so you likely got your noctowl somewhere that no longer exists.
Shellder isn't obtainable, and I don't think that if ever was. As for dratini, it is ametrine mountain, but I think we need the super rod for it so it's not available to us as of yet.