Half a story...
The idea was that all engineers join up, and get a common engineering training course. Following this, they then head off and specialize in that trade. This also allows personnel to move between trades, as they head back and complete the "bolt on" course.
So, imagine yourself in 2040...
We all rely upon contractors, not alot is actually fixed on site any more, its all modular changes. You are "down route", and an A Tech (Mech). You are servicing the A330 and your power set goes U/S. You get off the aircraft, fix the power set and get back onto the aircraft to carry on.
Some old folk will argue that this cant happen. But i suspect that an A Tech M, can fix a power set, with the correct training. Isn't it just a engine, a generator and a control system? If a Mech can change a wheel & brake pack on an aircraft, why cant they change it on a set of A/C Passenger Steps?
If all engineers get the same basic training, why cant a Squipper or a Gen Tech help out replacing an aircraft engine?
You get the idea....
Do more, work smarter, with less people..