5-3 Reacting to Receiver Stalk Block on Sweep

I run a 5-3 and play either Cover 2 or Cover 3 behind it. We are getting ready to play a team that runs pro set, two TEs and a WR. They are very effective blocking their sweep in part because the WR gives a slant look but then cracks back on either DE or Sam (lead back takes the other defender and they switch up each play). I am thinking of rolling to Cover 2 so I can free up the strong side corner. My FS can protect against pass and the corner will then blitz against this formation. That should give me numbers at the point of attack. Any reaction? Any suggestions on a different way to play this? My team is 10-12 year olds and they have no trouble reacting to a flanker or motion crack back but can't seem to find the wide receiver.

Thanks,

Coach Will