Actually, pace lines on doubles are fairly common, but staying in the same paceline for all 200 miles is not. Plus, it makes training a lot more fun if you have a group to share the effort, pain and feelings of accomplishment.
However, and all that said, I'm kind of winding down from doubles after having done 52, and living in Whittier I'm too far from the I.E. to join your group.
Still, it would be good for anyone in or near the I.E. who was into (or wanted to be into) riding doubles to join!
Rick / OCRR