One thing about union compared to league where I am, is that in union you can find your level due to way more numbers and grades. Prems have a really elite standard with crazy athletes but any other level of player will have somewhere they can fit.
Whereas in league, you've got guys who would be colts, 85s, prezzies, Bs, Div 1 in union, all smashed into one reserve grade.
Some of the kids really struggle with playing against men. I remember a pretty jacked kid 19, 20ish coming to a full league pre-season. His first game against Turngawaewae, ill never forget his face at full time, looked like he'd seen a ghost. His exact words were a breathless "fuck, that was a war." Never saw him again..

in union he'd have a Colts grade to prepare for seniors.
20kgs ago I had a couple of great seasons in the union u85s grade which was mostly an excuse to get on the beers with some good mates in the team.
Had a pre-season run with a Div 1 Bs union team in the league off-season a few years ago against Ohaupo. Div 1 Bs is the easiest grade we've got down here i'd say.
Scored a hat trick in 15 mins, felt like prime GI. Subbed off straight after, half because it was blazing hot day in Feb, half because I felt sorry for the old codger marking me. But least the old codger had a level he could still particpate in.
That's why I really hope this open age restricted grade in the ARL continues to grow and the game across NZ finds more participants so we can get more grades.