Complex sentence: The authors of this hypothetical example could have assigned numbers 1,2,3,4 to Allen, Beth, Cathy, and Debra and so far, they were free to assign to these fictitious subjects any numbers they wished.
Split into simpler sentences: The authors of this hypothetical example could have assigned numbers 1,2,3,4 to Allen, Beth, Cathy, and Debra. So far, they were free to assign to these fictitious subjects any numbers they wished.