Uruk-hai are bigger, stronger, and more disciplined than normal orcs, but in the very battle we are discussing it was Gandalf arriving with a thousand Rohirrim in the rear that caused the Uruk army to flee into the woods and be cut down, with less than half escaping.
And they might have even won the battle regardless had they not broken and fled, considering they still vastly outnumbered the Rohirrim. Maybe not though, since they were being led by an individual in Gandalf who could lay waste to scores of orcs with contemptuous ease.
Only in this thread there are three Gandalfs, who are arguably even more powerful.