Two words for how to PvP as Marauders that can't follow their targets.
Obliterate and Force Crush.
Marauders do ridiculous damage, Juggernauts have solid survivability. Hmmm they should group up to complement each other. To say they're not self-sufficient... people want them to be homogenized? Make Juggernaut reach a standard of survivability and damage that is the exact same as Marauders? That kind of destroys the line that differentiates the Juggernaut from the Marauder.
If you compare those two with the Assassin. Juggernauts have better survivability than assassin, Marauders do more damage than an Assassin. In other words Assassins have balanced damage and survivability but does not excel in either.