My ds will start prep in 2016, he will still be 4 and turns 5 in march 2016. I think that's ok for Vic..? My brother was the same and started school before he turned 5 (in nsw in the 90s).

Ds will be young, but at 2 he is the size of my 4 year old and if he is going to keep growing at this rate he will be bigger than his 5 year old peers at 4. I want him to blend in in the playground and I have faith I can get him school ready. He is a very active child so the hardest part might be his capacity to sit and listen.