The NZ TF is the same, we all have to pass. Funnily enough very few people struggle with a bft here but the run causes much more grief. Carrying your house is more important then running anyway.
I reckon a big guy should struggle with a pack less then a little guy as its far less of his body weight proportionally, Of course my logic makes no sense when you hear about 60kg guys passing selection. Its just grit at the end of the day.
I think its funny how older gents think the new generation is going to hell. Theres good and bad in every batch but most guys I know are bloody good.
Basic training would help them though. It helped me.