By Chris Rosvoglou The NFL offseason remains in full swing, as several free agent signings and trades are most likely being discussed at this moment. That being said, Colin Cowherd has already identified two offseason winners. “Broncos and Steelers — best off seasons so far,” Cowherd tweeted on Thursday morning. Denver made a huge splash last week, acquiring Russell Wilson in a trade with the Seattle Seahawks. The Broncos then bolstered their defensive line in free agency this week, signing defensive tackle D.J. Jones and defensive end Randy Gregory to long-term contracts. Pittsburgh, meanwhil…