The Warlord's Legplates (heavy) butt-cape physics do not work properly on Female Sylvari. I have tested it on a Female Norn, and Female Human, and it works correctly for them. The other Warlord items seem to have correct physics.
The easiest way to test this is to spin the character around in the Character Preview menu; the butt-cape does not flow, and just melds into a bunch of squares by the legs.