I’ve always leaned towards simplicity. On the track, I stick with one distance sets and manipulate pace, volume and rest to progress. For example, I will warm up, do 8 x 400, then cool down. I’ve asked a couple of individuals to sell me on the physiological benefits of doing mixed distance sets but they couldn’t come up with a reason. By mixed distance, I mean the classic 1600, 1200, 800, 400 sets or pyramids. I can understand the benefit in terms of variety for motivation but I don’t see the benefit in pure physical terms. Sell me on this approach.
You are looking for controversy where none exists, no selling necessary. Both examples you provide are nice workouts, and you are entirely correct that pace/rest/number of repetitions can be manipulated to change the point of the workout. As you go to the track more and more, though, the “variety for motivation” that you mention gets more and more important, IMO 