I don't think losing Fui is a huge loss at all.
Sure he has been good in his few patches, particularly in hitting the ball up.
But Peek in particular is the better option to have around during the finals. He is a very solid, experienced player, and I can't see how people think he hasn't played well this season. He hasn't had explosive patches like Fui, but overall I think he has been better.
Vs the Dragons, Fui's first touch was a knock on, then his 2nd touch, he fumbled again (a harder one, but still a fumble) and the Dragons scored. 10 minutes later he crashed over to score from a couple of metres out and thats a great game from Fui??
Sure, 9 weeks is harsh, especially considering Webb isn't facing half that, but I'd rather have Peek there than Fui anyway during the finals. More experienced, more consistent.