Firstly because the Saudis are not tribal like the Somalis
Then the Sauds had an alliance with most powerful Arab tribes, such as Mutair, Otaiba Al-Dawasir, Ajman
I personally asked Saudis why you love Al Saud and they said: In the past, the Arabian Peninsula was full of tribal wars, plunder and theft everywhere Al Saud was the one who stopped all this, united the people, and built this rich country for them
Somalis if a man from another tribe comes to their land, even if he will make them rich, they will fight him. Somalis do not know what loyalty