Laptop repair technician? That's just silly. Computer techs in general should be able to do both laptop and desktop work. The principles are essentially the same. Any competent tech should be able to fix a laptop as well as a desktop.
Trust ME, they are largely the same. There are a few things to be aware of, but as someone who worked for years doing professional repair, I can tell you that you're completely wrong. You add battery/power adapter, integrated screen and other peripherals, and that's it. It's merely an extension of existing troubleshooting and repair knowledge. The OS on them is the exact same thing you'll find on a desktop. Anything different is covered by common sense and simple logic.