arms muscle imbalance effects

If my left arms muscle is bigger than right arms muscle half an inch, is that possible can cause muscle imbalance on upper traps when I do the shrhuging because the other arms more bigger and maybe more heavyer

not likely, but if your having a muscle imbalance its pretty common in the arms as the dominant arm usually is slightly bigger than the other. I would recommend executing single arm exercises with dumbbells and cables, bands, etc…than using both at the same time.