Competitive will probably be some sort of experience flying passengers around in multi-engine airplanes. 2500 is the min, but most hired have a lot more (lots of retired airline pilots) and lots of guys from the regionals who had a lot more, though some do get hired at the mins. Unless your friends had a descent amount (probably at least 500 hours) of airline, cargo, charter, or corporate flying (or military flying) before they got their current instuctor jobs, I think they are gonna have a hard time getting hired at NetJets, even if a lot of their instuctor time is multi.
I wish everyone luck who wants to come here, but I do think it's unlikely to get hired straight out of instructing. I made a lot more instructing than I did flying air ambulance or for the regionals until I was a captain, but I knew I was gonna have to do something else to get where I wanted to go, so I saved up a bunch while instructing so I could afford the pay hit to do something else. Your friends are lucky they have such good instructing jobs, but eventually they will probably have to go get some other kind of experience before they can get hired onto a job that they will want to keep.