Can we expect a visit from the Home Office

We are a company who operate in Iran and the UK. We have hired three Tier 2 workers over the past six months or so, all of whom were granted Visas soon after applying. We are in the process of hiring a fourth worker who to our eyes and in terms of the requirements is every bit as eligible as the other four, however their Visa application has now taken almost ten times as long to come through with no decision as yet.

Is it likely this is connected to the number of workers from the same country we have hired and should we expect a visit to confirm we are complying with all the rules as a result? (We are!)

I don't want to overreact, but it makes me uneasy when a process that has reliably followed a certain path suddenly operates differently.

If you do everything by the book, you don't need to worry.

Sometimes they check more but it's not always about the company, but it could be about the applicant. I am saying there is an issue with the applicant, but sometimes the Home Office decides to make further checks and that takes time.

I have a friend from Libya. An amazing guy but every time he applies for anything, it takes ages. Some profiles trigger that but there is nothing to worry about.