The variant has the starting position below
Stone Generals can promote on the 14th rank to any non royal piece that blue has in the above starting positions, and they can move 2 squares on their first move. Other than having a different starting position and the above mentioned rules, the game is the rules are the same as in standard chess.
I think the ferzes would be valueless as they can't move and can't be captured, but they likely impact the values of other pieces as they affect both the movement of the king and the grasshoppers. Grasshoppers must be at least as valuable as dababas as they can hop over the ferzes laterally, and camel riders must be at least as valuable as camels as they can move like camels. I suspect that the camel is slightly more valuable that the alibaba but both move in ways the other can't so I'm not sure.
The position is very different from standard chess, so I think simply using the values the pieces would have in a position similar to standard chess might not work.