My thought is you gotta look at their body to understand how their tactics would be different. they got shorter limbs great endurance and a surprising amount of strength for their size. based on that recurve bows, crossbows, polearms, cavalry tactics, and pike formations or shield walls would likely be good for them.
Cavalry would be emphasized to make up for their natural lack of speed needed for quick maneuver.
Recurve bows allow for a heavier draw weight without making it as large and unwieldy for their smaller frames.
Crossbows got power in spades and dwarves are usually shown to be mechanically inclined.
If gunpowder is available in setting Dwarves should absolutely be going for firearms and Cannon.
Polearms would help make up for their lack of reach and they provide great leverage for their strength
Pikes would be good for anti-cavalry work which they need since they are generally not very mobile.
Shield wall would be great for the tunnel fighting and that shit is hard on your endurance but they got that.
with their longer lives they generally would be better trained than humans and while they don't reproduce like people they aren't quite as bad as elves either. so I would expect the average professional soldier to be much better than their human counter parts. especially if against a peasant levy.
in CQC I would expect a lot of Grappling to take advantage of their low center of gravity mixed with "low blows" targeting the knees, liver, and other vulnerable bits.
