I share this concern. Both our development squads and players on development contracts we seem to have a hell of a lot of nuggety players. Most players, even halves and fullbacks, are at least 180cn today. Yet both laulilii boys, faagutu, mason, feledy etc are all smaller.
Size isn't everything but the average back these days is pushing 186cm and 93kgs. The days of Matt Utais domination are over, some will still make it, but it's a gamble. On a development contract it doesn't hurt to take a closer look though.
Signing a 23 year old reserve grader who's 177 and 93 is a risk. Too small for wing, but paired with a larger player on the wing may minimise his being targeted. Our juniors seems to be either 194cms + or under 180cm. Strange that we don't have these more average build players