I know exactly what you mean. It takes a very good ear indeed to identify anything other than basic chords, although I spent a while learning jazz guitar chords which helped a bit.
I'm very much a right hand man, and if I'm not sure what the left hand should be doing I'll try a few things out. Sometimes I play a left hand chord with three fingers that sounds OK, but don't ask me what the chord would be called. I find that once you start replacing the 13th with a 6/9 and take away the number you first thought of, then that's where I start to lose interest completely.
I can play waltzes, polkas, javas, and maybe even tangos with the correct accordion chords, but once you get into stuff like the Girl from Ipanema then I have to rely on what I know on the guitar in an attempt to recreate all those maj7 and other subtle chord nuances that I cannot remember the names of. That tune sounds really nice on the accordion, but it was written for the Brazilian nylon string acoustic guitar, on which I can assure you it is far easier to play.