Winston Choo's time many lady officers came from SIA as requirement for lady officers included height! Now plenty of 5 feet 0 inches in the Armed Forces.
Still, it is not true that there are zero scandals in the SAF. Firstly, the regulars are monitored by Military Security Department (which includes many seconded from Police Force, Special Branch, ISD etc). And even if they discovered anything, it is kept within their doors until situation calls for the details to be released. And the best part is anyone suspected of anything is brought before their own Military Court. Typically, the punishment within the military is more severe than local courts. And even if the Military Court were to show some leniency, the Armed Forces Council (chaired by the Defence Minister) can impose higher punishment on the culprits, which they consistently do to drive home to everyone to toe-the-line.
Opportunities for one to be corrupt abound equally in both the SPF and SAF. It is just that the self-policing is better within the SAF.
It's not that there aren't scandals, the propensity to commit a scandal like having sex with vendors is rarer. As I said initially, if you get the scholarship, why on earth would you want to be a SCDF scholar? SPF ok, not to bad but it sucks in still. SAF is still the best, especially when you talk to foreigners. "Look, I got my one-star at such a young age! Didn't even have to serve in Afghanistan!"
Peter Lim and Ng Boon Gay could never get that. So their human nature took over.