Yes he did make them better, but the fact is they weren't his tactics.
Kreia said this during her last minutes. We know that she wasn't lying at this time because she predicted the death of Jango Fett at the hands of Mace Windu as well as the fall of the Republic.
He made them his own when he made them better, that's my opinion. The Mando's didn't use his improved upon Mando tactics so, what? How can they say "those are our tactics!" if they didn't even know what he was doing? =/
We know this? You can say this was 100% fact based on..? So what if she predicted that other stuff, doesn't mean she wasn't lying. Now I don't know why she would lie, I'm just sayin'.