This feels like a leap in logic to me. It seems that it is possible that a 'dark force' could be not operating as strongly in this galaxy as easily as the possi

This feels like a leap in logic to me. It seems that it is possible that a 'dark force' could be not operating as strongly in this galaxy as easily as the possibility that dark matter is not being present. Without a mechanism to explain why either one exists, I don't see how this observation could rule one or the other out. Not sure if this analogy works? Imagine one group postulated a new type of matter to explain the effects of EM radiation. Another group theorized there was a new force. Then there was observed some charge particles moving at constant velocity and the conclusion was the new matter theory had to be correct since we observed regular matter without the effects of EM radiation.