Incubi Numbers

I've just converted up my Vect model and as well as him have two other CC elements in my army; Incubi and Lady Malys. At the moment, those three squads will hop in the same Raider and multi-assault different units, but the idea that occurred to me was putting Vect with my blasterborn to fill up the extra transport slot, ditching an Incubus and taking Malys and the other four in a Venom. This loses me a darklight shot but in return I gain two splinter cannons and forcing my opponent to target prioritize.
So, should I lose an Incubus and do that? I'm worried that they might bounce off their targets, even with Malys attached (she can't take on 10 marines by herself). So should I go Raider or Venom?

Go bloodbrides... thats my opinion! XD 6bb+vect+malys=a whole lot of hurt

but in all seriousness, with incubi, you want to be able to destroy the unit you hit in one go, and without letting them counter-attack... unless you have a seriously good reason to take malys (for her abilities and crystal heart) in your local meta, I would suggest losing her in favor of a archon w/PGL (dolled up how you like), and MORE incubi, filling up the raider if you have the points available (and by losing malys, you should have the points to be able to do that).

Malys and 4 Incubi isn't a bad assault threat - the real question becomes 'what is it they're assaulting'?

On the assault on average;

Lady Malys will kill 1.77 Marines or 2.66 Guardsmen.
4 Incubi will kill 4 Marines or 5.33 Guardsmen.

So, versus Marines the squad will kill around 5-6 Marines on average meaning you'll do quite well verus 5 Man squads and can probably still kill 10 man squads fairly reliably though not as often in the first turn.

The unit would have issues dealing with anything with invulnerable saves, natch, managing 4 Terminator kills or 2 Stormshield Terminator kills respectively.

So, you can certainly go this route, but what you'll get is a fragile unit that is optimal at beating up things with good armor saves (or maybe very, very small squads of Termies) but should avoid dedicated assault units/larger assault units or else they will likely get crushed.