[quote=@Nytem4re]
<Snipped quote by Zarkun>

It teeters on the edge of canon and non canon. It's mainly only seen in Battlefront 2, I've never seen it anywhere else. Basically some kaminos went rogue and then basically said fuck it lets clone our own army to fight the empire.

It ended with the 501st utterly defeating them, as the clone army wasn't exactly ready at all. 

The reason given why it wasn't so well known is because they crushed it very quickly without many people knowing. I doubt anyone other than darth vader, boba fett, palpatine, and the 501st knew about it. 
[/quote]

Then perhaps it being successful is in our best interest plot wise. Though perhaps it would be better if it wasn't for some time.