This is stupid bickering.
ANY engineer worth their weight in salt should be able to adapt to the situation or section they find themselves in.
Do you really need to fix that defect in the line situation ? Is it airworthy ? Can it be deferred until the next A check ? That is the question line guys ask themselves with all the support of the DDG, MM and maintenance watch. At the end of the day it is just a mindset.
Now if the line guys can't get out of that mindset if they get posted to base maintenance then yes they are useless from a company perspective and a drain on their crew mates who have to pick up their slack.
Its the same thing when an ex heavy guy goes to base maintenance and start getting all pedantic about scratches in the paint on an oil filler access panel. Unless the guys are totally incompetent and have no sense of commercial reality, maybe being a utility worker is a more suitable position.
It really does **** me when the more holier then thou gang get up on their high horses and proclaim that mr engineer from <insert section here> can't do this job because they're not here in the first place.
We all came from somewhere. Once people get off their high horses and show a bit of respect around the place who knows they might actually learn something.