[Mobhack]

The chance is for a hit, which is nothing to do with a kill. A hit can cause a morale check, or the unit to take cover or pull back for example. Or it may just be deemed a close miss, causing more than average suppression (soft units if near-missed can gain S). Or it may actually kill a crewman. A lot depends on the receiving unit's morale and experience ratings. Green and unkeen units will melt faster than veterans with high morale.

Thus the only thing you can say a largish %age shown as a potential to-hit score is a better shot than if a smaller %age was displayed. That and experience gained over many battles.

But size 0 units are a special case, where direct fire to-kill rolls tend to get converted to high suppression:
IF Range is long - so as range goes beyond 1 hex, they get more difficult to kill.
UNLESS using a sniper class. Best counter-sniper therefore is a sniper
OR its an HMG team. Next best option, with the bonus effect of blast circles "spreading the joy2 to any neighbours of the size 0 unit.

So - spread your fire over the size zeros, till they are suppressed and better in retreat or rout status. Then close and kill with a 1-hex shot in the face from a full size section, a tank or APC, better yet enter the hex and melee them with a rifle section or cavalry. Tiny units dont like the bayonet.

And of course, little teams get crucified by explosives. So liberally stonk any area you think they may be with your arty.