I'm not sure that makes sense to me. Same number of squadrons, presumably the same number of DH slots, so unless you're talking about the year where the screen was pilot heavy...? We're still only talking about a handful of people. The three I'm thinking of also didn't have pristine records, however "good" they were, IMO.
There were 3 or 4 guys I knew personally that were strong runners with good records but didn't make the cut, what do expect with 25% selection rate? Theoretically the same number of DHs but they always seemed to stuff extra ones in Prowler squadrons, we had 8 at one point in my squadron, harder to do in Growlers.