I thought I'd create a new thread about this, in case others play BI1 at maximum difficulty (4-move limit enabled under "Settings").

Below is a list of maps that can be beaten with just 4 moves/attacks per turn. If anyone has beaten more, I would like to know and extend the list accordingly.

Battle Isle 1 - first 15 maps
CONRA, PHASE, ECOTY MOUNT, FIGHT, RUSTY, FIFTH, VESUV, MAGIC, SPACE, VALEY, TESTY, TERRA, SLAVE, NEVER

Moon - first 7 maps
LUMIT,LUNAR,LUTOF,SONIX,SOWYN,SOSOO,SONAF

Desert- first 7 maps
BLOCK , WATCH , LAGUN, BIRMA,SERPT,RAMBO,YUKON

Note that the difficulty level becomes very high for some maps. I found the first two maps of the Desert data disk to be particularly challenging. In both maps I found only a single solution for the first few turns. Other maps are much more forgiving.

After playing the Moon data disk some more, I now think all of its maps can be beaten with just 4 moves/attacks per turn. It is simply very hard in some cases, but not impossible. Maybe this data disk had been created with that limit in mind.