Saquon Barkley worked out his contract squabble with the New York Giants and showed up for training camp. Josh Jacobs is holding out with the Las Vegas Raiders. Le'Veon Bell once sat out the entire season after getting the franchise tag. Different running backs. Same problem. No solution on the horizon. NFL teams have devalued running backs to the point where Bell's franchise total just five years ago was significantly higher at $14.5 million. The tag for Barkley, Jacobs and Dallas' Tony Pollard was $10.1 million this season. Bell played on the franchise tag in 2017 but sat out the…