Today we managed to get the Abandoned Tools on Boromir and had the right objective come up to just exhaust the Hero with Abandoned Tools four times to win the game.

So, er, I upped my threat several times to repeatedly ready him and did it all at once. So what normally takes four turns was done in one. And I can't see anything in the rules that says I shouldn't have done.

Is it really legal? Seems a fairly easy and cheesy way to win what is otherwise a very hard scenario,

It's cheesy, but yeah, it's legal. haha
Good gaming.

tottaly legal and also a wise move... 4 turns is +40 to your end score, you even with the threat gain you came out way on top. Beravor draw decks also own in this stage.