Yes, crownies would be quite formiddable
. Think about it - they have swordsmen, spearmen, archers, axemen, crossbowmen, lightly armoured militia (in the more recent sets), heavily armoured knights, pikemen (though a minority), wizards, DRAGON RIDERS YEAH!
and heavily armoured foot knights. Not to mention their well-defended buildings (lots of artillery mounted in the towers) and small, effective siege weapons. Very varied and adaptable faction.
However, they do have two weaknesses:
-NO NAVY OMG!
-No "ranger" or light cavalry for guerilla tactics