Drop the dracon with the blast pistol. For 20 points you get a gun that'll never be in range and 2 extra attacks. It's not worth it.
5 reavers total, 2x cluster caltrops? Correct me if I'm wrong, but isn't it 3 per cluster caltrops?
Also, I've played around with the Duke a few times, and the
DS isn't worth it, the combat drugs never go your way anyway, and
TBH he's only about as good as an average archon, for more points.
The shardcarbine trueborn aren't needed unless you're up against hordes or
MCs. You have 39 wyches, so don't get that much anti-inf elsewhere. You've got enough there to deal with a whole WAAAGH!, so drop the reavers and use the points to upgrade the other trueborn into blasterborn.
After that, you'll have a decent list