1. It is high risk because of the need to take up to three season out of a players career to convert them to new positions and because of this medium to high risk coversion process it creates depth issues that leave teams unprepared when the successful conversions are injured or at the end of their careers.
2. It is much more efficient to take players out of college and have them play the positions that they played in college that you scouted them playing and determined they had potential for the NFL.
I think I have been pretty consistent about that. And to suggest that having a 270lb man chase 200lb RBs in pass coverage may cause leg injuries is far from a reach. It's a logical possibility.
My preference for the 4-3 is no less credible than your love for the 3-4. You like apples and I like oranges. However, I think the argument I have made about replenishing talent in our 3-4 is looking to be very true as the stars of the last 7-10 years fade out.