Pre workout is indeed important. Why someone would not do this baffles me. I would suggest a good complex carb source for long lasting fuel, and a lean protein source.
Pre workout nutrition is indeed as important, maybe more important than post workout. This is in fact due mostly to the fact that if your body does not have adequate "fuel" to draw on, guess what it will draw on?
There is some studies floating around out there also that show biopsies of leg muscle with a pre workout protein drink, and a post workout protein drink. Seems the pre workout drink showed more uptake of amino acids. This was in fact sited years ago, and with the advent of the pwo drink mixes, was kept down to sell products in my opinion. I read this study a good 5-6 yrs. ago. I believe it was again Paul Crib who researched this(AST sports science).
Anyway, my thoughts and experience would lead to one simple conclusion, why not do both? Makes all the sense in the world to me.
As far as the servings, this will simply relate to digestion times, more food, longer wait.