They really don't. If every specialist was balanced and equally powerful, and assuming the players are at the same skill and intelligence, this game would likely last indefinitely - at least for domination. For a regular mining game it would come down to who built the most mines first and just defending them. It's the power of specialists that can break stalemates and resolve games that arguably already last too long.
Added balancing would make alliances and betrayal more important, a pro or a con depending on subjective opinion. I personally think it's a con because most people I've met in this game are not very savory. Alliances won't guarantee resolutions either. More balanced specialists will probably also cause more people to use multiple accounts, and we don't need that.