Okay so according to your logic, the only reason Emmitt Smith is the leading rusher in NFL history is because Barry Switzer and Jimmy Johnson. The only reason Jerry Rice has the most receiving yards in NFL history is because of Walsh and seifert.
He has the second most passing yards of all time. He has the most passing touchdowns of all time. He has 6 Super Bowls. Most career wins. He won three mvps. Four super bowl mvps.
Who would want him? He is 42 years old. He is in the tail end of his career. Miami and Chargers are going to draft the younger qbs. I think Tampa should keep Winston.