Some more thoughts on the scenario:
This time relations version, settings: Emperor, Normal, No techtrade either way, agressive ai, no raging barbs
I decided to start with the sheaim as i never played them and their position in the scenario looked very challenging. The start was easier than expected, although the terrain is really hard to come by, the whine and the gems help at the start though. I noticed you gave them 5! goodie huts, is this some sort of bonus for their hard startloc? Which is indeed too hard imo, heres a screenshot why.
At turn 115 ca. 8+! Barbarian units came at once from the north until turn 130with a total number of 20+. Now imagine this on raging barbs

I must admit i had to load an earlier save. having the lichking around isnt healthy, also the halfcircle landbridge to the east is a notorious barbarian spawn, surely a player can handle that, the ai will suffer heavily though.