I got an answer from user "ishmaeltheforsaken" at Nexus forum. https://forums.nexusmods.com/index.php?/topic/5145800-mesh-problem-all-female-guard-use-wrong-armor-texture/?p=45438055
However, I found another UNP mesh replacer that working perfectly. I'm switching to use it instead of using this fix. It is UNP Female Armors SE.