Undrafted free agents face an uphill fight to a roster spot as rookies. But in the case of unselected tight end Tanner Arkin, he could fit perfectly in the New England Patriots offense.That’s what SI on Patriots’ Ethan Hurwitz wrote Saturday. Hurwitz formed that argument a day after Arkin addressed how he could fit into Josh McDaniels’ system.“We use a lot of different personnel,” Arkin said to the media after the Newton North High School’s June…