What is the effect of adjusting balance on game play? Obviously balance 1 is supposed to easier than balance 10. What is actually adjusted? Is it numbers of enemies, AI ability, damage model or what?
The 'balance' setting depends entirely on the mission designer. As mentioned earlier, the enemy / friendly units could be set to appear / go missing, depending on the balance level selected. Or, it could be possible to have no such settings written to the mission scriptfile.