I personally don't get people's deal with Shadow of Mordor/War Shelob the entire game is only meant to be a fun AU with loose canon, I don't even think even it's creators will deny this. I mean is really hard to accept they made Shelob a shapeshifter using loose canon for justification under those circumstances? I personally won't be losing sleep over it or dominate my headspace, and neither should any of you.
The only way the Shadow series has affected my perception of LOTR canon is that I can no longer picture or imagine Celebrimbor canonlogically as anything other than his in game counterpart unconnected to plot and the general geography of Mordor itself as shown and thats it, beyond that it's a fun AU fanfic game that's in its own universe.
In fact, I personally wish that Shadow of War had solidified the whole AU deal more with an alternate ending where Celebrimbor remained sane based of dialogue choices between him and Talion and once they dominate Sauron they decide the best course of action is to haul his ass back to Valinor for justice averting the War for the Ring.
I agree that it's loose canon; the argument I'm making is that it's actually pretty compatible with book canon, and if anything, far more compatible with the complexities of book-canon than the very simplified take of movie canon.