I've heard the same things and understand that point of view. However, I chuckle when I hear an analyst say that Henry will struggle because he can't consistently make defenders miss in the backfield. Um, hello, if there are defenders consistently in the backfield during running plays then there are much bigger problems with the offensive personnel and/or play calling. Additionally, there have been plenty of running backs whose game isn't predicated on shake n bake and making defenders miss. Just a couple years ago (2014) DeMarco Murray won the 2014 NFL Offensive Player of the Year Award - I remember that season well because I had him in fantasy that year
. He rushed for 1,845 yards and 13 TDs. Murray is just about as straight line of a runner as there is. That's why when Murray was traded to the Eagles he struggled mightily in their system because it forces the running back to go east/west instead of north/south.
I think that fact underscores the importance that Henry gets drafted by a team that runs the proper offensive style that suites his strengths. Henry is a bigger, faster and more durable version of Murray. There's a role for Henry in the NFL it's just not with every team.
I think the fact that Henry is somewhat scheme dependent is the main reason he slides out of the first round..