You don't need to too care about the overall DSE results of these too schools as it is affected by the quality of the S1 intake. If you look at their 2025 DSE results, SPC has an edge over SJC in 332A, and 4+ but the difference in 5+ is not significant. SJC 5*+ is on par with SPC, if not better.
If a boy can do well at SPC, he can be equally well at SJC.