Of course, Chaos is the strongest race in HoMM 4. And about something else that hasn't been discussed yet: the skills of the Rogue and the Lord. Don't you think that the Rogue's skill is much more useful? And if we compare magic, hypnosis, illusion/mirage, these are the only decent spells. Well, maybe also ice bolt. But can they compare to Chaos magic, like disintegration?

1) The Lord's skill is much more useful than scouting. 3 Titans per week is very strong, especially against Castle, and it will be easier to buy them back.

2) Let's compare magic. The Chaos faction has a very limited set of spells. There's almost no one to cast buffs on, and against direct damage, you can always find a way to defend. A Titan with accuracy will wipe out half of the Chaos army (they have two advantages: protection and growth). With teleportation, either Nagas or Titans will be sent to the Chaos faction's rear, and they will survive for 2-3 turns. Castle will have a hard time against Titans and Nagas. And who else does Chaos have? Ifrits and Nightmares. And both can be targeted with Berserk or Hypnosis against the Chaos faction or Castle.
Another advantage: Order has faster access to tactics compared to Chaos, which is an additional army buff.