Both Mandolore and Canderous Ordo (soon to be Mandolore) praised Revan's tactics. Take it however you want but it's truth and I believe it means that Revan is a great tactician.
As for the oneness of the force thing - the novel never says that. This means that you are speculating. Does it seem like he was one with the force? Maybe, but the book never says that he was one with the force so you can't assume this.
But you're right about using two sides of the force. No arguments there.
We could go into Revan's dueling skills, force powers, and other stuff, but you didn't mention that in the original post - so I'll stay on topic.
The two Mandalore's praised his tactics? That would be a kind of character statement. He used Mandalorian tactics, combined with his superior Jedi numbers, to gain the victory. He did not create a tactic, or set of tactics, that completely outwitted the Mandalorians. His aggression caught them flat-footed, and that caused their downfall.
The description in the book causes confusion for casual readers who do not know the subtleties of the Force and do not know what is and is not canon. Using both sides of the Force is against G-Canon. Which makes it impossible. Once you have eliminated the impossible, what remains must be the truth.