I heard from my friends whose boys are studying in Diocesan Boys' School Primary Division that many of the P1 DGS are graduated from CCKG. But CCKG does not have K1.
I heard from one of my daughter's school parent said that DGS would admit more CCKG students because:
1) Many of them are of same religion of DGS
2) CCKG likes to admit elder age girls & boys (same consideration as DGS)