My view on warm-ups constantly changes, so I'll link Pavel's thoughts through the years instead:
Nice Collage Of Information
This is a very nice collage of training warm up information.
My perspective and Pavel's are the same; less is more effective when it come to warm up.
For many individual, extended warm up is emotionally driven and has little carryover to any physical warm up necessity. A pervious example are lifter who are able of Squatting load of 700 lb plus, warming up with a 45 lb/20 kg bar.
It makes virtually no sense to start off with an Olympic Bar that t is 6% of your max training set. It more of a head thing or some type of ritual rather than a physical necessity.
The doctrine of extended Warm Up has be engrained brainwashed) into their head and is now their religion belief, metaphorically speaking.
Advising these individual there is a more effective approach and requires fewer Warm Up is heresy.
I understand. That is my initial reaction to anything that is new and goes against what I have learned.
The Mental Side of Training
To reiterate, I addressed the head issue in my previous post. In other words if something F's with your head, it an issue and need to be addressed or catered to.
As in dealing with my friend that felt he need extended Warm Up, we kept the same number of Warm Up Set but decreased the Repetition in each of them.