stealth_nsk
Deity
Likely it isn't going to be a walk in the park to raze a city state. Askia would likely be ganged up on by the other Civs who would likely not be pleased with him, especially if they were friendly towards the city states or had designs on them. This in addition to the City States who would throw their lot in with the other Civs to prevent "the madman".
City states ask for help when you declare war to them, not when you start razing them. And since conquering city-states is obviously possible, I don't see any additional constrains for razing.