Although students worked with pairs, the first 20 minutes of class felt like starting a car up on a cold winter morning after a week of it being idle. (With no class on Friday due to our rotating schedule, this is probably an accurate analogy.) We had many mismatched pairs and I had to work with individual groups of students to explain how the graph of the derivative matched with the graph of the function.
So, would I do this activity again? Most definitely. However, I think I would create a slide with just 3 matches in the future and have our class work on that together - asking for verbal justification of why students paired certain graphs together. This would be the equivalent of letting the engine and car heater run for about 5-10 minutes before driving the car. Perhaps this would have led me to not having a stalled start.