I wonder whether, had they chosen to contact the aircraft outside their sector, the Skyguide controller would have heard them. With VHF radio being line of sigh

I wonder whether, had they chosen to contact the aircraft outside their sector, the Skyguide controller would have heard them. With VHF radio being line of sight, the aircraft would probably have heard them, but Skyguide would be based at a ground station that was perhaps occluded by nearby mountains or other buildings. Where I live, I can't pick up a VHF ground station which is nearly in my line of sight only fifty kilometres away.