The miney is the backbone of the hero army, which in Legendary Wars serves the mining purpose. Suprisingly, the miner doesn't appear to fight in a regular battle except for two (2-9 and 4-4). It's the level where you have a limited amount of gems and you are supposed to kill the boss miner Lemmy. It mostly only appears in action levels.
Their attack is similar to the dwarves', but with a slightly higher attack rate.