Which units would you replace in the Sylvan castle?

That's right. According to myths, many wars started because of them. And in reality, many conflicts arise precisely because of women, and many people have died because of them in duels (now I'm talking about duels in a broad sense, including various confrontations like shootouts or Viking-style duels). By the way, it's interesting that Celtic mythology constantly features female warriors, even though archaeological and historical sources assure us that women did not fight among them (yes, and it would be strange).