Unstoppable pen.
I agree with Southgate not making changes (except the enforced one).
England were always likely to be untroubled by Panama.
Give the players chosen as your first XI a chance to perform and build confidence. Nobody should be dropped after one game.
If he'd dropped Sterling and Rashford had come in and done well against limited opponents, then Sterling's confidence is shot and he knows he won't get back in. He becomes a passenger in the squad then. That's not good man management.
Rashford and Vardy are useful subs with their pace and will get opportunities if England do progress through the tournament.
The manager will also have to look at what selections are best suited to playing better opponents later on.