Many sports games, especially football, are played over two legs (=two games), so each team gets to play in front of their home crowd. A leg is a part of the contest.
Scraping a win means winning by the smallest margin possible.
When one team wins easily we call that "strolling".
stroll = take a leisurely walk
Basically, he's saying that England are only marginally better than the team they are facing, and they're going to have to work hard to get the win they want.