Interestingly enough, in the days when I used to follow racing much more closely than I do these days, some of the worst jockeys were in the NI, often in the CD. I never really used to have any Southern jockeys on my "wouldn't touch with a barge pole" list.
And the problem in the SI is not the jockeys as much as the shocking programming. That is why form can be inconsistent. And form is equally inconsistent in the CD where a horse can fail in an $18,500 race at New Plymouth and then come out and win a $40,000 at Trentham. And vice versa. That would seldom happen in Australia.
Half the horses in any given race in the South aren't racing over the distance they would prefer or in their preferred class or after an ideal gap, but they have to take any opportunities available to them. If they wait for the perfect race coming up next week they have every chance of being balloted out.
I feel quite sad when I see a typical $18,500 low key race in the south with 12 starters and six of the jockeys are from the NI, often the very top jockeys like Kennedy and Doyle. How on earth are southern jockeys to gain experience and skills if they can't even get a ride at a low key meeting? Some of them have to drive 6 hours to get two rides. It must be a pretty dispiriting occupation. And when they ride at certain tracks with about six people in attendance and no atmosphere they must wonder why they bother.