Here's a little story to illustrate my point.
Many moons ago, I was on ops with my Regiment in a badly civil war ravaged country. We had Ptarmigan as the main communications system. The mobile part, SCRA, has two types of equipment, the Central, and the Terminal (ie the user). In our regiment, we had "inherited" 5 or 6 of these Centrals that were badly u/s.
Now in R Signals, there were two types of techs in my day, radio and systems. The systems techs fixed Ptarmigan. Now, out in the field, the systems guys had looked at these Centrals, and failed miserably to fix them. My Regimental Foreman of Signals (equivalent to an RAF JENGO, though a WO), asked me to go look at them. Now as a Radio tech, I could have told him "Sorry sir, but I dont know the first thing about these". Which was true. Or I could have said "OK sir, can do". So I went and sat in the back of these things, and struggled with a mountain of AESPs(~APs), hand cranking diesel generators in -10 conditions. After a day or two, I got three of them working.
The next day, I happened to be on duty bod, during the Regimental management conference. Cue Regt FofS, when it came to his report. "Good news, I have three SCRA Centrals now serviceable. Without the likes of Cpl Roadster, I would be dead in the water." Now the CO knows I was a good egg. Guess what, I got an A confidential.
Wind the clock on several years. I need a favour from Manning & Records (our Innsworth). Who's the big cheese? My old CO. "No problem, Sgt Roadster".
I didn't have to help my Regt FofS, and my old CO didn't have to help me.
Some lessons in there, methinks.