We can only speculate, the fact is though. This didn't happen, Revan did go to war - so debating about this won't get us anywhere. However Revan could never have listened to the council, because in his opinion what they said amounts to doing nothing, they advised caution, that was it, no battle plans or strategies. If Revan didn't leave another Jedi would have, it was inevitable.
That's actually wrong. The Jedi weren't just sitting around playing 'go fish', they were analyzing the threat. They were not apathetic, not in the slightest. They were analyzing the threat and saw the big picture. Revan and the Republic saw only the Mandalorians. The Jedi Council knew that something else was driving them. They knew that war with the Mandalorians would lead to greater atrocities. Master Vandar practically saw the Jedi Civil War. They knew fighting in the war would lead to greater dangers. They were also still recovering from the war with Exar Kun. They knew that waging war would lead many down the Dark Path. And you know what? They were right.
I've made my opinion on the Jedi Council's inaction clear. Yes, they were wrong in completely ignoring the Mandalorians, but we can see why. I believe that they should have involved themselves in the war, but in an advisory capacity. This would allow them to prevent Jedi from falling to the Dark Side, as well as Jedi casualties. I would even put Jedi on planets to defend them. Jedi are defenders, not aggressors. Revan abandoned the Jedi teachings and fought the Mandalorians on their terms. He matched their aggression with his own, leading him down the path to the Dark Side.
I don't think we can condemn them for their inaction. Everything they said would happen, did happen.