It seems to me your mixing up several stories. There were some Mexican bandits who wanted to rob the Church in Mexico. To pull off the robbery they needed help so in Silver City , NM they recruited some cattle rustlers
( Curley Bill ? ) The Cattle rustlers then helped the Mexicans pull off the robbery. After the robbery--there could have been 18 horses--with most having riders--so maybe 4-6 pack horses? Maybe 2 pack horses? They rode
back to the United States and entered what is now near the border of New Mexico and Arizona ---they rode up Skeleton Canyon--
The leader of the American cattle rustlers told his companions that he would sent two riders forward in the canyon to make sure it was safe for everyone.
These two men rode forward up Skeleton Canyon to a perfect ambush point--called "The Devils Cauldron"---when their Mexican partners reached the Devils
Cauldron--the two men waiting in Ambush opened up with Winchesters murdering their partners.
Later people would see this Ambush site with all the bones of the dead and call it " The Devils Cauldron" located in Skeleton Canyon.
90 % of all this money / loot was spent in the saloons and brothels of Tombstone.
In the 1960's along came a man named KVM from Segundo, Colorado and he recovered about $ 700 from this site after searching it very thoroughly.
It was in a house on the opposite side of the street as Examino that I learned this story.
Since over 35 years have passed--the names of the outlaws have been forgotten as well
as the exact dollar amount of the recovery. But well 18 mule loads of treasure

Which
church in New Mexico or Arizona --if robbed would have that kind of money?
Mexico is a poor country--back then you would be lucky to make $ 10 a month--
or $ 25--30 dollars in this country! You have to use common sense.
Barton