[Edi]

The dwarves are fun, yes, but only if you find mines that are conquerable. If the nearest mine is 15 turns march away (extremely unlikely but possible), it's going to be a slow game and probable defeat.

Or if the nearest mine gives you a scouting report to the tune of "Iron Mine. There are 32 units here, 17 Dwarves and 15 Dwarf Warriors", you can forget about it right then and there...