I’d be tempted to stick Wallace in a number 2 shirt and let him learn the ropes there. He’s tough enough, physical enough, and young enough to adapt. He’s just not got the beef to be a serious contender in the back row. I suspect, given his overall athletic demeanour, that he may also be able to throw a lineout ball reasonably straight. With a couple of A-grade props on either side to look after him, it could be an interesting experiment.