Hi there,
I'm a principal applicant from Tanzania living in Qatar. Not sure about applications from Saudi but I believe if you have everything in check ,then I hope the process won't take too long. Usually for background checks, applications coming from Middle east are forwarded to London Visa office or the principal applicant's country. From what I've heard London VO is usually very busy and that's why some applications take a long time during the background check (3-6 months).However, I'm seeing alot of improvement this year. I'm one of the applicants of the month of June 2021 (Outland) and I can see from the tracking tool, things are moving for applicants whose papers are in London VO. So Just make sure you don't leave any signature, you're detailed as possible in the form and supporting documents, and pray that everything goes well
My timeline is in my signature
All the best!