I really ought to know the answer to this one, but it came up last night and nobody seemed to know what to do.
Naval combat in the South China sea. Both the CW and Japan have convoys in the area, the CW has a cruiser in the 4 box, and 4 in the 3 box. The Japanese have a big task force in the 4 box, nothing in the zero. Search time.
Now, if only one side finds the other, we get
Only one side succeeds
If only your side gets to include units, then you must pick at least one (or more if you prefer) section containing committed enemy units. Only those enemy units are included in the combat.
Just because you choose to include the enemy units in a particular section in the combat doesn’t mean that your own units there are also included. They must have been included by your own search roll.
But in our case, it was raining. The CW rolled a 4, which only lets the cruiser in the 4 box find, and the Japanese roll a 2, which lets the I will kill you fleet in on things. The question is, can the Japanese force the inclusion of the ships in the three box, beating them all up at once.
I could have sworn the answer is yes, but I can't seem to find anything in the rules that justifies it.