I find it's easier to use the Canadian Army WO appointment titles (RSM, CSM, BSM, CQMS, Pl 2IC, etc) and leave the WO rank out of it when talking to US folks. It avoids confusion. The US WO is very similar to the Russian system: a creature between officer and NCO, usually promoted from the ranks for technical ability. Ours, in the Army anyway, is really employed as a higher form of NCO equivalent to the top three or four US E-grades. If we want them to do officer things on a permanent basis, we use CFR or Limited Duty Commissioning to promote them.
Cheers.