Hmm some interesting comments.
I have a mixed display of European Bison and Red deer. 3 mature bulls with 8 hinds (1-21yrs old) and a big 16 point stag. Why.. because it makes a very interesting display for members of the public. If a visitor is interested in a display they will then read information board and hopefully learn something about the animals. The more educated people are about a species the brighter the future is for that species.
My stag has in the past got a little pushy with the bison, they have always backed off. The enclosure is about 6 acres with 3 (soon to be 5) distinct areas of the enclosure that can be partitioned off if need be.
375 mag... What do you base your conclusion on ? A one off that has been sensationalised by the press ?
Bison and stags are both extremely dangerous animals in their own right, I know this first hand. It is entirely feasible to keep these animals in mixed displays without any problems.. if they are managed in the same way as any other DWA. That entails experienced, qualified, people overseeing their well being and adjusting husbandry accordingly.
There are several parks in the U.K that have mixed displays including bison and red deer, living together all year round.
Regards
N.F.W.M