GMs and activated Conspirators have similar effects when played, and they both require you to pursue a strategy that will allow you to set them up (getting GMs, activating Conspirators). But in practice they're not so similar I think, because getting GMs and setting up Conspirators are really different "tasks" if you will, requiring different kinds of openings (well, often I think) and other different buys (Gold can be a necessary stepping stone to GMs, while you almost never want Gold in a Conspirator deck). And they require you to adjust your strategy differently in the late game: with GM it's more about knowing when to stop buying more GMs and start greening, with Conspirator it's more about keeping the Conspirator chain moving along as you green, at least as best you can.
I guess what I'm saying is: they're actually hard to compare, because of these differences and perhaps more importantly their cost.
