Put yourself in their shoes old mate and you might have a completely different perspective.
Their local manager presents himself as nothing short of a boofhead and has been recently in all sorts of strife with the company and the troops for behavioural faux pas'.
Secondly the General Manager who openly admits he has very little appreciation of the operational details of the areas he manages and "does not need to have one" is passing judgement and imposing rostering arrangements on the guys purely just to make the bottom line (read achieve his bonus) look better at the detriment of not only the working conditions and morale of the PER engineers but ultimately the entire Line Maintenance operation around the country, with PER being used a the "test case" or thin end of the wedge so to speak for him to achieve his ultimate goal (re-read achieve his bonus).
This guy has a strong recent history of outsourcing for no great benefit to the company (take Jet Turbine Services for example)!!!
I'm sure you pilot typies would be up in arms if you had this sort ****e being rammed down your throats with little assistance from the current workplace regulations.