[Micah]

They're important and probably a vital strategy in a large game, but they're not unbalanced. Diversifying is important to the late game, and that means that everyone will have access to clams and/or blood stones at some point, and once they do the income disparity won't continue to grow between natural clam nations and ones that have to find indies or empower to pull it off.

So it can be an important, maybe even vital, strat for long games, but it's not unbalanced any more than researching is, which is also a pretty important strategy for the late-game.