Anyway , something big happened last year where i got into a big fight ! I managed to control this huge guy with a sankyo . I realised that placing a lock on someone who is trying to beat that crap out of you is different from the dojo . Also , a lock can be countered . I brought this up to my teacher and could not get a proper answer..
You said you were able to control a huge guy with sankyo. It sounds like aikido worked for you.