@sidereal
I guess this is talking about background characters? Because the mother and the human maid don't look the same, the witches don't really count as "side characters" and then I think that's the full list of female supporting characters in the movie.
The female background staff in the inn do all look pretty similar, but so do most of the men if you discount the moustaches and hats. Maybe there's more to it, but to me this quote seems to mostly be about pragmatic prioritising of animator effort for crowd scenes.