I like it. I ran just one of those hound units (14 hounds and a Herald) in a 1500 just the other day and it was my MVP. Absorbed unholy amounts of fire, took pressure off the rest of my army while pressuring my opponent and still survived to eat his warlord.
I would tweak a few things though. Move the grimoire to one the Tzeench heralds. Your opponent is already going to want to shoot the dogs, so make them decide whether they want to kill off the force multiplier for your army or the rabid dogs ready to eat their face.
I would also drop all of the greaters on your heralds. other than the greater ether blade, there's not a whole lot there that Heralds will benefit from. The greaters are great for
DPs, not so much for Heralds.
Use some of those points to get another lesser for the Khorne Herald without one. That nets you Axe of Khorne, and it's boss. Replace the Locus you have to Locus of Greater Fury on both. That nets you rage, hence 2+ attacks on the charge. You
Consider dropping your horrors down to 11 and reserving them. Also consider dropping a unit of daemonettes. Use these points to get 7 or so screamers and discs for you Tzeench Heralds. Now you have a much more mobile fire base that is resilient and your opponent won't be shooting at your troops. They'll also be able to keep up with the hounds, buffing them if necessary.
I'm not too experienced with souldgrinders but I can say I have run both the flesh hound unit and the mini ScreamerStar to great effect thus far. Hope that helps
Automatically Appended Next Post: Ha I liked your idea so much that I went to the trouble of some tweaks for you. Here ya go, see if you like it:
HQ
Herald of Tzeench: 175
ML3, Disc, Locus of Conjuration (+1S), Exalted (Grimoire)
Herald of Tzeench: 150
ML3, Disc Exalted (Portalglyph)
Herald of Khorne: 130
Lesser, Locus of Fury, Juggernaut
Herald of Khorne: 130
Lesser, Locus of Fury, Juggernaut
11 Horrors
11 Horrors
13 Daemonettes
13 Daemonettes
14 Flesh Hounds
14 Flesh Hounds
7 Screamers
Soulgrinder
MoN, Phlegm
Soulgrinder
MoN, Phlegm
So pretty much the same core except you've lost 10 Horrors and 4 Daemonettes in favor of a mobile base for your grimoire and buff masters that given the right psychic powers, can be nigh unkillable. You've also gained the Portalglyph so with any luck you'll make back the daemons you sacrificed. Seems pretty solid to me.