I was certain that it was 0,5 on all and haven't looked in the army. My mistake. Still puzzled by the cost. Umbra is not a good LT choice without CoC available. Why make it even more unattractive?
Because Infinity is not balanced to that precision. SWC costs on Lieutenants, in particular, seem to be unnecessarily punishing to some factions.
You really have to maximize the primary strength of Onyx which is the Unidron link buffed by assisted fire. The plasma weapons also pick up shock, so does the missile launcher... If you are moving out with a spitfire Unidron it is BS14, 5dice, ignores cover, has shock.... you need to be trying to make as much use of that as you can. Also, the AVA of noctifers as 2 can be an important draw. With Bit and Kiss having been added recently it is a very viable sectorial IMO. Just be careful with your LT if it is a nexus, or instead run a combi Noctifer LT and keep him in marker state most of the game.