I’d hope that Dwarves have only slow units – so yeah, catapaults and cannons and the like would be great, but also really slow and tanky knights that can draw aggro… they’d have massive health and deal massive damage, but can easily be picked off by faster enemies. They have to rely on their crossbowmen allies (slow moving, slow to fire, good range and damage) or emplaced siege weapons to deal with enemy rangers, while the knights hold the line and never back down.
Conversely, Elves would rely on speed to never get caught. They’d be squishy, but deal good damage and have great rangers and spellcasters. I’d also imagine they have very fast swordsmen and possibly spearmen who can fight “from arms’ reach”, hitting and running with their swords or relying on the spears’ range to keep enemies at bay. At the same time, traps would be extremely useful in this strategy since they allow the Elves more opportunities to break up large enemy groups, to stun really dangerous enemies, or simply buy more time for the archers/mages to thin their numbers.