Arbitrary (adjective) existing or coming about seemingly at random or by chance or as a capricious and unreasonable act of will

https://www.merriam-webster.com/dictionary/arbitrary

Article “Why Collaborate” Page 1 Paragraph 2 “I have enjoyed voluntary,informal collaboration wth my firends, but I have resented being forced into arbitrary, mismatched teams in the name of comical correctness.”

The definition of the word allows me to see the contrast of voluntary collaboration when it comes to working with others. Lupton was letting the reader know she does not like being forced to work with people. She continues to explain that she hates being forced to working with others so much she holds a resentment.