Voting Green has the exact same effect as not voting. Yeah, it shouldn't be that way, but it's the way it is. There's wanting the ideal system where third party votes matter and there's pretending it already is an ideal system

You don't get to an ideal system by voting for people that won't have any power to change things. You make a difference by writing to and calling the people who do have power and ensure the people you call are at least sympathetic to what you want.

It is indeed not that complicated.