This debate has no substance to back it up. Lamar Miller was a 3 down back in Miami for 3 years before coming here. Lamar Miller had 3 seasons of close to 200 carries, and had a 1000+ yard season. Duke Johnson averages like 50-80 carries per season and has never rushed for more than 400 yards in a season. How are you guys even trying to compare the 2? Lamar Miller came to Houston assuming the role of our workhorse back. Duke Johnson came here as our 3rd down back, and now you are hypothesizing him as our workhorse 3 down back. If you want to have some "theory" that Johnson could be a workhorse back, enjoy your debate, but its based on no evidence. Lamar Miller proved himself in that role for several years.