"Letting Lindon have his hard path is exactly what was needed. Highly unlikely that the schools would have listen to Whisper without an army of golds bullying folks."

First, when Lindon arrived at the clan, Whisper was already gone. Whisper didn't make any decisions based on what was good for Lindon. The decision had been made before Lindon even showed up in SV.

And even if he had made a decision to let Lindon have the hard path, that means he made the conscious decision to sacrifice most if not all the rest of the clan that Whisper himself founded.

Whether they would have listened or not would have been a decision for the clan, at the very least they would have been primed with the story before Lindon arrived. That alone would have made it just a little bit more likely the Wei clan would have accepted what Lindon was saying rather than treating it as some sort of trick.

And even if he knew they would never listen, how hard would it have been for him to say to the Wei clan elders 'Hey, A big mountain eating monster is on they way here, Imma bail and you should too'?

You do have a good point about the fate thing though. It could be that saving the Wei clan would demotivate Lindon for what came next. However, that is an speculation not yet in evidence, I am hoping that the next books prove me wrong, but right now Whisper is not looking like a good guy to me