Gentlemen, "Conflux" is one of the three strongest castles in Heroes III.
In almost 90 cases out of 100, birds appear in the Conflux during the first week. Their speed and growth rate allow you to develop the main hero quite well in the second or third week, and possibly even defeat an opponent. Besides birds, the Conflux has the most powerful ranged unit – "air units," which have excellent speed (giving them the right to the first move in battle against almost any unit), a good amount of health, and powerful ranged attacks. However, they have one drawback: they are twice as vulnerable to air magic. And another important unit in the Conflux is the "psychic" (psychic elemental); magic has no effect on them, and they attack (without retaliation!) all units standing around them.
These are the global indicators of a "cheating" castle, as you say.
For an experienced player, controlling the Conflux is almost a guaranteed victory.