It’s a mathematical formula.
On one hand, sometimes it can be a benefit to double your armed forces in order to completely demolish your enemies and assimilate them (or just their women).
On the other hand, if too many women are killed then that limits how many kids will be in your clan in the future. So in this case, it’s better for clans to not have women fight.
It has nothing to do with foid worship or being cucked, it’s simple mathematics and logistics. Sometimes it’s useful in order to completely dominate your enemies, and sometimes it’s not useful it will limit your future population if too many women died.