First of all, I don't really know of anyone calling Konstadt rebellion to be led by anarchist. They were ardent communist who became disillusioned over time due to poor working conditions.
Secondly, out of the 15k men who held the fort, it's thought that around 10k escaped to Finland during the fighting, all while killing around 10k soldiers of the red army.
I don't really think this really fits within the scope of the argument that Lenin murdered 9 million people.