Unique Tame Beast bug(?)

Not sure if bug, but it doesn't state on The Natural Order node for Spirit Walker that we can only have one unique beast, full stop. It says we can only have one summoned at one time, so I have big monkey on one weapon set and big chicken on the other but swapping sets keeps deactivating one entirely across both.

Please tell me it's a bug because I want to swap between bosses on the fly like a pokemon trainer.

Edit: this is what I mean - https://youtu.be/Wlk9QfBiGnc