I believe you have it backwards, the M40 was impact and the M38 was random delay. A lot of the references for submunitions are less than accurate.
DJ, my data does not show the golfball type submunitions being carried in the Lance missile, though they were in numerous rocket warheads and may have been in the Bullpup missile.
M38s, M40s and M32s could be either dispenser dropped or released from warheads. The MK5 Mod 0 dispenser (MK 15 cluster) carried 2020 M40s, or 2020 M38s as the MK22 cluster (Sadeye). The SUU-30 carried 2025. My favorite is the SUU-24, it carried 38,520. The Honest John submunition warhead carried 4800 of the M38/M40 or 3093 of the M32.
The M32 used the M212 fuze, the M38 used the M218 fuze and the M40 used either the M219 or the M291E1 fuze. The M219 series is impact only. The M218 has an internal sack filled with viscous fluid, when the fluid is forced out it fires.
Here are some of my golfball variations, plus my Honest John submunition warhead - behind the other little pieces..