CAIS grade 1 vs local school

Got accepted by CAIS year 1 and my boy has a band 2 private primary school as back up. I believe my boy can survive better in international school while he may be the neglected type in local one. Someone says it is hard for the kid to go from
IS to LS. But the fact is my boy has foreign passport and I am going to send him to overseas university one day. Rationally, I know IS is better in his case but I am still worried if my choice for him is right!

Anyone sharing the same situation