I was thinking about this combination to get around Sarumans threat lowering ability. The idea is to have Fall of Gil-Galad on Saruman, destroy him to lower your threat by 13 and put him back with Landroval. Does this work or is Sarumans text still active? I am assuming it works, because Landroval says "put the hero back into play", for that he would have to be out of play and so text isn't active, but I'm not sure.

It works. The moment that saruman leaves play after being destroyed, fall of gil-galad triggers. Saruman's text is no longer active, so you reduce your threat by 13. You then trigger landroval, which brings Saruman back into play.