From an outsider looking in I think he is failing to utilise the attacking talent England have. His support of Maguire should raise alarm bells, he shouldn't be afraid to rotate Kane every now and again.
I think Dean Smith would be a good shout for England, plays attacking football, knows how to use Grealish but I don't think the FA would even entertain my suggestion.
Back on topic Southgate failed at Boro, failed with U21s and still got the nod for the Seniors and you could say he should have won one of those previous tournaments.