Not unless the orcs on the wheels walk backwards
Anyways, let's study each faction's weaknesses and advantages:
Well-organised with formations that would just be pretty much invincible against regular infantry, excellent heavy and light cavalry, plenty of "heroes" (king, wizard, dragon rider), excellent defensive strucures, good economy. However, no navy, standard soldiers not very good at individual combat.
: Will keep fighting even when missing 1 (or more) limb, no fear of pain/death, scary, lots of soldiers, powerful wizard (and witch?), dragons, have a navy. However, would not be able to swing weapons with much force, not smart (cannot suddenly deal with a new situation), no siege weapons.
: powerful and skilled fighters, good war machines, virtually impregnable mountain strongholds, fearless. However, no navy, no archers, very little flexibility.
: Numerous, excel at offensive combat (huge siege engines), giant trolls can smash up even the strongest shield wall, battle wheel invulnerable to a direct assault (skellies would never work out how to stop it), great navy, fierce fighters. However, constantly eating each other, trolls somewhat unpredictable, require vast amounts of wood to keep their armies going, not the most wise of creatures, few defensive structures.
My conclusion? an all-out battle would be pretty even, but the crownies' good economy lets them retaliate even after a loss, thereby tipping the scales in their favour.