Just looking over a couple of thing, Shaun Johnson was also a rookie in 2011, interestingly enough from what I could find, 15 rookie halfbacks have made the Gf in 116 years, not great odds, but not bad either just over 12%, however on the other hand just 7 over the age of 30 have won a GF and only 2 over 35 which is just over 1%, so it’s a very rare feat for a senior (over 35) halfback to come away with.
Going off statistics its more likely that a rookie will lift the trophy, in saying that there’s a caveat attached, bit like a super add, “past performance is no indication of future performance”. Should Chez lift the trophy he will set a new benchmark as the oldest half back to raise the trophy. Cronk holds that tittle at 35 years 305 days, Jim Craig was the only other 35 yo to do it, 1930 with Western Suburbs.