My son is 7, diagnosed 10 months ago. His ratios are 1:9 at breakfast, 1:16 at lunch and dinner. Insulin to carb ratios just are what they are. Your child needs what he needs to survive and be healthy. His needs will change over time, but not only in one direction. My son I:C ratios are changed every few weeks at the moment, sometimes even more frequently, but it's not just to increase the dose, sometimes a change in the other direction is needed.
There really is nothing to be gained or achieved by comparing ratios with other children, or by worrying about it. Type 1 brings enough worries without losing sleep over this too. You can't control it, you don't need to control it, so what is there to be gained by worrying about it.