Higher Game
National Socialist
On hills, the conquistador can plausibly defend tanks from antitanks.
Cavalry can too, but it's cooler to do so with such an old unit. It might have the most longevity of any unit, excluding the fast worker. For what it's worth, pikemen regularly stop vanilla cuirassiers, too, and the cuirassier is solid enough already that a massive improvement would be unfair.
Numidians and jaguars at least have a niche, despite their lower strength. The dog soldier regularly loses to catapults, chariots, archers, and horse archers where a regular axeman would be better. Simply being better just against other melee units isn't worth the strength penalty. Sitting bull has protective totem pole archers anyway, making the dogs absolutely pointless for defense (and we know they can't rush). Well, they're pointless anyway.

Numidians and jaguars at least have a niche, despite their lower strength. The dog soldier regularly loses to catapults, chariots, archers, and horse archers where a regular axeman would be better. Simply being better just against other melee units isn't worth the strength penalty. Sitting bull has protective totem pole archers anyway, making the dogs absolutely pointless for defense (and we know they can't rush). Well, they're pointless anyway.