Time to solve the horse mystery once and for all. It seems to me there are two options:
a) Cusser's theory is right, the goof is in the first scene. (He takes the horse he uses later and the horse he uses in Santa Cruz isn't there at all.)
b) Cusser's theory isn't right, the goof is in Santa Cruz scene.
The black horse is definitelly Indio's.
Manco after shooting the three men:

Indio when setting off from the desolate church:

Manco in Santa Cruz. Notice this is a different horse, without black tail and with different markings on head (as you'll see later).

Manco on the way to El Paso:

Indio on the way to El Paso. Here the scenes change quickly, so that probably causes the confusion with black horse.

Manco in El Paso:

I have more pictures of Manco on the same brown horse. Please, take my word for it, I think this is enough pictures for one post.
