Rock Slide in OO to fend off Fletchinder, while retaining coverage on other Fire-types.
When talking about Granbull's lack of reliable recovery in Overview, emphasize Granbull's common exposure to Knock Off hampering Granbull even more by removing its Leftovers.
Not sure if you should mention the part about Granbull switching into special attackers in Overview, given that it doesn't respond to almost any of them and thus the idea shouldn't even be entertained.
In C&C, 'Fire-types' can probably just be combined into 'Special Attackers', just with more notable mention due to their resistance to Fairy. There also must be more special attacks in the tier that can threaten Granbull, such as Hydro Pump, Thunderbolt, or even Scald and whatnot.
The physically bulky Pokemon section can include more examples, such as Uxie, Gourgeist, Carracosta, Mega Audino, etc., Pokemon that have ample time to do what they want.
Why not mention Haunter and Mawile in the Poison-types and Steel-types section, respectively? It should be especially noted as they have the greatest immediate damage potential among their respective types.
QC 2/3