The thing is that one on one, in an ideal environment, a Sathanas is very easy to destroy, as long as you blast it for long enough. However, eighty juggernauts are going to sweep through whatever you have in no time, not to mention the huge fighter complement and warship support. In order to disarm a juggernaut, you need it to stay still for a while, and you need space from the hundreds of fighters bearing down on you. In addition, you need something to stop it from just cruising through your star systems and killing ur d00dz, so to speak. However, anything you put in front of it besides the Colossus is likely to get blasted to pieces within two seconds.