I'd still lose the 2 splinter cannons on the warrior squads. They're just not very efficient. You're going to be moving in order to effectively utilize the rapid fire/splinter racks combo to be most effective, which means you're using the lower profile for the cannons. So you're basically paying 10 points for 2 additional splinter shots.
With the 20 points you save from not taking those, you could give your haemonculus a vexator mask, upgrade the venom blade to a power axe, and take a torment grenade launcher on their raider.
This will make the haemonculus more surviveable in a challenge by forcing the opponent to take a leadership test at -1 or not be able to attack you for the round. Then, at initiative 1, you get to make your attacks at S5 AP3. If you could free up 3 more points, I'd add a soul trap to the mix for kicks.
Alternatively, prior to seeing your updated list, I actually liked your old one better, and was only going to suggest getting rid of the 2 splinter cannons for splinter racks. I personally don't see a problem with going with a minimalist HQ such as a haemy w/ liquifier. Could always just throw him in with a trueborn squad to discourage people from charging the trueborn.