Reavers shine for their bladevanes, which is why they are fielded in larger squads of 6 or even 9. If you need some mates for your wyches, you can take a unit of 6(especially since you need not fear our enemy the heldrake) to bladevane the tar out of a unit before you charge it with wyches. However, if you do this you might consider swapping that agonizer for cluster caltrops for the same cost. Also, if you're expecting minimal mech presence you might even take 3x disint. cannon ravagers, maybe putting extra points into another blasterborn venom or something. Those are all pretty minor though, the list seems solid.
This isn't even my FINAL FORM