Hi Benjamin,
I have no idea, maybe it's a good idea to let them face the direction of the Three Killings but as I don't use Pi Yao, Chi Lin or Fu Dog, I cannot tell.
I think they clash horribly with the style of my home - but it's my personal decision not to use them. I only make sure that I don't renovate this area in the respective year and I have been fine so far.
Take care,
Astrid