>On average a 6x5 board contains a bit more than 8 combos, and making less matches than what is available is penalizing both
It is optimistic to believe a player that don't know anything about the game will do 4 combos regularly, much less 8. The few times I did more than 2 was by pure chance after all. The balance of the game can become lopsided if the expectation on the player are so high.
>My hunch is that it will add a fixed amount of damage to the player output, so lowering the enemies' hp by a fixed amount would achieve the same effec
Guaranteed damage gives the player a sense of progress and that their actions are having an effect on the game.