I'd be hesitant to start a WASH Qb if you get penalized for INT's. This is for obvious reasons. Also, Spurrier will likely move QB's in and out - some series Matthews some Wuerful. You can't start both and I don't see any predicatble way to know which one will have the better game.
On the flipside I think Gardner and Thompson are good WR starts. If the INT's happen, its no skin off their backs. + if the skins are down, which they might be a lot bacause they still aren't a great team, (see Matthews & Wuerful) they will have to throw even more.