Bradley shouldn't be High 8-C. He's superior to most alchemists, yes, but not through strength, but through a significant advantage in both speed and skill. He should be 9-A for cutting through tank armor, and Greedling should probably be 9-A as well for being able to briefly overpower and wound him. No one else scales, though you could argue that other Homunculi should be comparable. Scar was overpowered by him the entire fight and killed him with deconstruction alchemy.