Same Speed at Different Power

Problem is My friend and I want to do the same Workout, but end up separated due to not same FTP. It would be nice to let the one with higher ftp to lower it’s speed (power to speed ratio) to match the speed of the lower ftp. This way we can push each other effort in the training session. In short you’ll be riding side by side if your doing the same effort even if you have  different power output. 

Idea coming out of my mind is, A leader create a training session, then a user will join that training session and speed:power ratio will adjust accordingly. same effort same speed. if you’re not doing the effort required you’ll be left behind, vice versa.