From some basic research if you don't control the ground you don't control the airspace.
And besides airspace is a place for mutual cooperation rather than 'control'.
Somaliland can issue it's own clearances meaning there are planes taking off and landing without Mogadishu's authorization that means planes flying through Somaliland airspace at least need information from Somaliland. Somaliland can even issue flight level changes and reclearances and they could ignore them but based on other similar situations they would just get confirmation from Mogadishu and then follow the direction.
So basically if you don't control the ground and can't ground flights and have state-like entities in your 'sovereign territory' that can afford the necessary equipment, let alone operate international airports with mulitple carriers, you don't control the airspace.
