Reading this thread made me curious: left-handed people make up a reasonable percentage of the population. Is there any historical mention of units consisting completely of lefties, holding shields in the right hand, placed on the right flank?

Makes sense, but it might not fit into the general unit recruitment/equipment schemes. I'm sure the Spartans killed/exiled lefties for being non-conformists... Maybe it created a weakness at the point where the righty/lefty units met in the lines. Just curious if there is any historical evidence of this.