You should definetely want endurance, and armor. Strength is next important for Sith Marauder. The sith juggernaut is a melee tank, and is focused on armoring. The marauder is focused on strength, and you should try to make up for the lack of armor.
Sorry, that is exactly the opposite of what he should be doing.
Endurance is for tanks. If you favor endurance over strength you are giving up dps, and dps is what marauders are all about.