UAE vs Saudi Arabia
The working age population(18-60) in SA is approximately 21 million whereas the total Emarati population in UAE is 1.5 million , not sure how many are working age. Obviously , with better opportunities in the UAE and a smaller base , there has been a strong dependency on expat workforce which will decrease over time as the state strongly encourages and incentivizes the local population to take up jobs that have been traditionally expat only.
In the Saudi case , having a large young unemployed population is not an option that any government would like and they should and would focus on "Saudisation" , it makes perfect sense for the future of SA.
Masalama