Typically I'm one for experimenting to understand how things work and react, however, I am always against experimenting on animals, it almost never works out in favor of the animal. Despite the fact that there have been many cases that show otherwise, I understand that you believe you're giving them a better quality of life by putting them together. Ultimately, this is your experiment, but as the person running the experiment I was curious if you have a set procedure and taken the proper precautions for the experiment and to protect the animals?
Given that a fight can break out and be over in a minute with both sustaining serious and possibly life threatening injuries or even in the death of one, do you have appropriate monitoring for aggression or are they typically left for extended periods on their own?
What is the backup plan if you do encounter aggression or a potentially life threatening situation?
Do you have the expertise and resources available to treat injuries, or, more broadly, what is the course of action for injured animals?
Does the person monitoring the animals have the practical experience and knowledge to assess the behavior of the animals (stress, aggression, etc.).
You've said this is a temporary situation, what is the targeted end of the experiment?
Experimentation has procedures, controls and boundaries. When the end result has already been generally established, just throwing some animals together to see what happens without these controls and expect different results I see as just cruel.