Tell the truth, I had same problems with Rome: Total War 2 until they were released an update. Since this moment lags and heating troubles disappeared. That is why I think this problem is soluble by patching. Moreover, It is not a reason to exlude laptop users from the global list. They also bought the product and have a hope for the some kind of support.
http://www.larian.com/forums/ubbthreads.php?ubb=showflat&Number=495843Read the sixth line down...
PC and Mac players can now also play together on-the-go with the newly-implemented "Laptop Optimized" mode.
Yeah, about that optimized mode...