What's the point of this map? Is it just to fight tooth and nail to capture the city portal on the central island? And then endlessly struggle against AI opponents with infinite resources?
You need to go to the center not only for the teleport, but also to complete the quest with the Fangarm and get the horn...
In general, the map is tough because the resource spawn is very scarce. You also need to build a fortress, the distances are large, and the AI opponents accumulate so many resources and troops that it implies a game that isn't just about brute force, but also requires using your brain to win against the artificial idiot (who, by the way, effectively uses expert mass berserk and many other things in HotA).