So Sidious created Maul and Dooku? Come on. The only one who was "created" as Anakin. Thats why he is refered to as "the chosen one". Plageus was able to do it once, Palpatine knew Anakin would be all powerful, killed Plageus and waited patiently. Plageus could cheat death, so who knows how old Palpatine really is or how far back he goes. The Sith's one ultimate creation will be there un-doing.