It really seems that this makes little practical sense, as it would be harder/more awkward to draw the gladius from the right left for most legionaries.

I've wondered this for a very long time. I'd like to consider myself a Roman military history nerd, and yet I still have not gotten a concrete answer to this from either historians or my own research.

One answer I recall stated that it would be difficult to draw the gladius if a legionary's shoulder was pressed against his scutum, and that against an enemy line, so the sword was kept on the right side. This make little sense, at least in my mind. Are there any concrete answers to this question, or is most of it speculation from scattered sources that can go either way?