Personally, I think the Corsairs make for better Trueborn/Sybarites. The capes make them stand out from the average Kabalite Warriors.
Lokhir would make for a great Archon, but his dagger should be replaced with a pistol.
The one to his left could be a Lhamaean, or a second Archon. No idea what to do with the assassin though.
The Mage Hunters could be used as Mandrakes. Their crossbows would actually fit for that role, since Mandrakes are now better at close-range shooting from cover than in close combat.
Other than that; yes, definitely more splinter weapons. If you like them dual-weilding, you can still attach the holstered rifles from the Raider crew to their backs.