CAT scores, IMO, are a pile of crap and are dangerous information if used to determine a child's future.
My eldest had very average CAT scores and I was told his secondary school options were limited. A year later a couple of them went up, one by 45 points. I put zero faith in them whatsoever. They do not take into account motivation, drive or discipline which make a huge difference.
My DS was nearly kept back due to his CAT scores. Then, he was actually given an academic scholarship for his school.
My other sons CATs are alright, a bit higher even. Others have better CAT scores than him but my DS is in higher sets.
My DS is predicted good grades for GCSE but this is all based on how he is performing now, in year 10. You cannot predict GCSE's from CAT scores. My son has a healthy dose of academic ability, motivation, determination and he is very disciplined.That is what makes a difference, not the results of a kiddie IQ test.