Most trades address each team’s special needs. A linebacker for a running back. An offensive tackle for a pass rusher. Unless one of the players is a complete bust, both teams can often get away with spinning the trade as a positive.
Much rarer is the trade of two comparable players at the same position. Two teams are publicly declaring that they simply like one player better than the other. There is no place to hide if one goes on to clearly outshine the other.
This past off season, the Eagles and Rams made such a trade.