They have a large supply of type rated guys in the UK waiting to move there from Ryanair. I for one know of 7 captains and 2 FO's at my base alone who have had applications in with them and never had a call, they are all type rated and ready to move over in 3 months.
Where are they from? Jet2 try to recruit people local to where they are from, even if they can't provide them with their local base straight away.
In answer to the question, I suspect that they are looking to take disassociated people who have discovered the green field of the desert/far east isn't quite so green that have moved there from their original home territory which is Jet2's back door and are looking to "get back".
Having said that I would suggest that you advise your colleagues to phone Jet2 recruitment and speak to the people there, they aren't like that Ryanair lot