RETDPI, I remember one such when I was wet behind the ears and didn't know trade groups as such, for the youngesters this was before TGs got numbered, and we had a TAG. We treated him as any other SAC - we had a clerk stats and a clerk admin not to mention the clerk ops.
Only after a while did we discover he was a TAG, by then it was too late, he was remustered to clerk admin. All it usually needed was an application of tlc and education in the right proportions.
My current ex-TAG is a very steady pair of hands and was telling me of some outstanding postings he had. Because he was not in anyone particular TG he was employed where ever, when ever - bit like GD Aircrew even.