Not sure if this is a bug or was planned by the devs but Nianthi legendary units have a max capped damage rating that is much higher than that of a war elephant which sort of goes against the order of general unit strength being that of Infantry < Calvary < Occult < Bestiary. In addition, War elephants are also more expensive to purchase in the Black Market which also makes them more expensive to revive. (Even though they are weaker)

Now its not like Nianthi requires some rare units to reach their max cap. In fact just some normal wardens/ballistae will give the Nianthi +4200 which already surpasses the max cap of War elephants. In fact, Nianthi have even more defence than their Hero counterpart. The only case ever where a defensive legendary of its class (Infantry, Calvary etc) is larger than the attacking counterpart.

Please correct me if this was intended but it seems counter intuitive than an Infantry Legendary Unit has more defence than the Calvary Legendary and also has more defence than its Infantry Offensive counterpart (considering this game generally favors offence)