Blasting someone with lightning isn't a story element significant enough to say that it makes the inquisitor story like sidious. The inquis does NONE of the scheming that Sidious did. Darth maul traveled the galaxy unnoticed...very true, but he didn't travel the galaxy looking for ancient tombs and spirit ghosts...he was killing mofos. (I don't watch the cartoon series so IDK what he does there, but ill guess and say Bioware was talking about movie maul not cartoon).
....also...how is vader a marauder? he would obviously...i mean obviously, be a juggernaut. That is if you're making the distinction between class specialties..which i wasn't.