As a Flemish person, I wouldn't say Flemish and Walloon have the same accent in English, but I guess I'm not the one to judge. What is funny though, is that _in English_, you can sometimes detect different Flemish accents, i.e. when someone is speaking in English, I can tell whether they're from West-Flanders, from Antwerp, or from Limburg (in the east of Flanders). Their typical Flemish accent seeps through in their English. Also, the Dutch have the same accent in English as they do in Dutch (compared to the Flemish variant of Dutch).