Behemoth's really a very RNG matchup-dependent piece with its passive, it has no effect on Tiger/Dove/SoulFlare/Princess, less effect on weak minions like Pawns, 'average' effect on Militia/Salamnder, and maximum effect on RoyalGuard++/Fireball/Pikeman armies. I think the maximum-effect case makes it worth even higher amounts, and the current "about +6" is balanced around its average effect.

But yeah, it's totally accurate that Behemoth's passive also denies a weakness of expensive pieces and it's even better cause of it.

-main_gi