I understand that, but you have to realize that P-3s had better MAD booms and had the opportunity to “map” predetermined areas to plot out a map of anomalies under quiet times, very handy in comparing new data to old.
I’d think the A/C versions were counting on less sophisticated detection myself. Just a dumbass’s opinion - two cents and all that.
It's been a number of years for me, but I understood S-3s to have MAD booms as well...probably not as large as the P-3, but probably capable.
As to the mapping point, P-3s were certainly designed with more of a "patrol" mission in mind, where S-3s were more for "on-the-spot" surveillance. An S-3 might get a sonobuoy hit, make a MAD detection, and then drop a torpedo. Their range is much less, but missions were similar.