Seems as though time is a differentiater in this poll, for the longest time Jim Brown was considered the greatest football player.. rightfully so, but as he ages and there is less of a remembrance of him his "greatness" fades..
Compare to Brett Favre, who was not one my fave's, but he has dropped out of the top 5.. if we come back to this poll in two or three years, will Cam Newton have attained prominence??
Top 5's or even top 10's are often interchangeable and there is not a lot of difference, except for "regional homerism"..
Sometimes comparisons does not reflect the time that a player was "great", how would Johnny U or Montana do in this day and age, salary cap has become an equalizer. San Fran loaded up with a lot of high priced(relative to today's salaries) talent, did that make Montana greater?? Conversely if Brady played on those "loaded teams" would he be considered differently??