Let's not get carried away by England's result against Iran. The 6-2 scoreline doesn't really reflect the game - it was probably more like a 3-0 or 3-1 match. Iran have very good forwards who can seriously test more pedestrian teams like the USA and Wales.
England could also lose to anyone in a one-off match.
Did you see the Iran game? The Iranians clearly weren't playing like a team and the terrible situation in Iran and the double pressure on them from the regime and the people will continue to influence their performance.
England could in principle lose to Wales or the US but that isn't particularly likely, their last match is against Wales but I don't see them sending in the reserves, too much prestige at stake (the tabloids will be merciless if they lose to Wales). The realistic US path is to beat Iran by as much as possible and only lose to England by one goal.
