I don't agree that he plays to a higher standard than Grealish personally. They are a different type of player. Grealish's goals and assists may not be spectacular but he holds the ball extremely well and draws plays to him creating space for others to use. He would have been a massive asset in helping us break down teams in this tournament.
Rashford is out of form and has had a poor season but he has played well for England in the past and has competed in 3 tournaments. Maybe Gordon is better, maybe he isn't. Gordon has had one better season so far but wasn't at the level of Rashford's best seasons. Time will tell on that.
But my point still stands. He doesn't look like he trusts Gordon to go on and change the game for him on that left when he needs a goal. If that's the case why didn't he take a player that he would have used. These are the players he chose from a very talented bunch. He chose to go away from the players he used through the qualifiers (Grealish, Rashford and Maddison) and replace them with Bowen, Eze and Gordon. And now he won't use them. That's on Southgate,
He also chose not to take a proper recognised LB to play while Shaw was recovering. Again that is on Southgate.