The Sidar don't have too much "flavor". If I remember correctly, the only think the script looks for is slow movement surroundings (if that is what mobility -1 is)? So they probably get last pick of starting positions.
Assets\python\entrypoints\CvFlavourInterface.py
pCivFlavourInfo = CivFlavourInfo("CIVILIZATION_SIDAR")
pCivFlavourInfo.addPreference("MOBILITY", -1)
civFlavourInfos[pCivFlavourInfo.civ] = pCivFlavourInfo
Assets\python\entrypoints\CvFlavourInterface.py
pCivFlavourInfo = CivFlavourInfo("CIVILIZATION_SIDAR")
pCivFlavourInfo.addPreference("MOBILITY", -1)
civFlavourInfos[pCivFlavourInfo.civ] = pCivFlavourInfo