That is pretty much what I suggested a while a go:
Though now after the release of the game and 2 more pantheons I have changed my opinion.
Making heroes a kill reward makes them way to hard to get. I think Eagle and Jaguar Warrior deserve to be hero units. Chinese also have heroes that are pretty good against human units so I think Eagle and Jaguar Warriors can also be heroes that are decent against some human units, the same way Atlantean heroes are still good at doing the thing the none hero version is.
Jaguar and Eagle Warrior were the elites of the Aztec army so they shouldn’t be spamable human units, in my opinion.