Are there any downsides to lowering the costs of the unused(in ranked) War Elephants, Shotel Warriors, Condottiero, Teutonic Knights, Turtle Ships, Steppe Lancers and Siege Towers?

Age of Empires II: DE II - Discussion
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Condottiero have a +10 infantry armour bonus.
That lets them take 10 less attack from hand cannoneers. But it also reduces the attack of Catapracts and Jaguar Warriors etc…
Perhaps they could get even more secret armour or attack types to buff them ^^
Like, for example: +5 damage against siege weapons or +2 armour against unique units.