Simply Awful Bestiary

I was in a map hunting beasts, having the sextant that duplicates beasts on, got happy to find a Craicic Chimeral, after completing the map went immediately to store the beasts with Bestiary Orbs. imagine my surprise when i found only 1 Craicic Chimeral, instead of 2 - sextant is on and active, i even use the map enchant so that the map doesnt consume sextant uses. The only possible explanation is that since i killed the beast in question i killed another red, that replaced one of the Chimerals. now how is this ok or logical? shouldnt a new beast at least replace the oldest in the Bestiary? instead, a new beast replaces another that was killed seconds ago. i find it totally unacceptable! at least give us a button to somehow empty all red beasts we dont need!