Both dramas are based on hotel settings.
In Hotel King, the female lead is the heir of the hotel.
In both dramas FL and ML work together at the hotel.
Hotel King is more dramatic than King the Land.
Curiously, the word "King" is present in both dramas, and the hotel name in King the Land is "King Hotel", the inverse of Hotel King. Any hidden reason? I don't know.

If you liked TFF maybe you also like Tatta Hitotsu no Koi. A japanese drama with similar themes, a rich girl, full of attitude, chasing the "ordinary" and hardworking guy she falls in love with. But she hides a secret from him. Many similarities, a very beautiful drama too.