OK guys. I have the secret to velocity. Here it is. Read carefully, now. 8)
Velocity = a + 2 b + 10c + 5d .....................
Many variables, all working together or even against one another. Increase one and decrease another and you could have a zero effect. Some variables can be factored up in terms of their effectiveness relative to others. Increase how well you use variable c and you get 10 times the benefit of variable a.
The hard part, of course, is assigning real items to a, b, c, d, etc. The point here is that they all go together in a very intricate, dynamic way to end up in velocity. We will argue forever over which one is which and how much more effective it is over another.
Some pitchers use variable "a" more than "b" but make it work out in the end of the formula. Fast tempo CAN result in high velocities, if other things are there. Slow tempo CAN result in high velocities, if other things are there to offset the slow tempo. That's PROVEN in the big leagues.
It's all a game of trade-offs and what works best for a particular pitcher. Now, does increasing certain variables result in the same velocity at less stress? Probably.
How will we ever agree on any of this? I really don't know. That's why I don't like "absolutism". Lots of talk about science but it's still not very good science, yet. Marshall insists that his science is such that he has the secret to high velo with low stress. Mills insists that the science he references in his book proves that he's right. Others disagree with both.
Lots of fun, isn't it?