I think Smooth Airperator has hit the nail on the head! As a former Monarch FO who joined Primera and very recently joined SAIL I recognise a lot of what he says. At Primera there were plenty of cultural issues, miscommunication and misunderstandings but mostly colleagues got on together and actually produced a reasonably good working environment. Standards at Primera were either satisfactory or much better but a few of my colleagues were not up to the task. They passed the joke of a selection via Skype and a few online tests only then to be failed in the sim on OCC or on a line check. I suspect dealing with cultural challenges at SAIL and a better recruitment process would help.
The trainers I knew at Monarch were almost exclusively friendly and very able instructors. They had high standards but were practical as well. They were always fair and I don’t expect that has changed. However, if you are a charlatan, you will be found out!