Dealing with Vigilius Defiant Guard

Im, not sure if many of you have had the displeasure of playing against the new guard detachments from the new Vigilus Defiant book.
A mate of mine runs the following: 3x tank commanders (1 with the 3dmg relic cannon), pask, 2 manticores, 1x valkyerie + scions with plasma (vigilius allows him to disembark after moving the plane), and 6x 10man guard squads..

He combines this with the 'old grudges' WT and overlapping fields of fire etc, and completely destroys half my army in one turn.
How does one counter this list efficiently?

Im running the following: 1x haem (with mask), urien, 3x5wracks, 2x3 talos with haywire, 3x ravagers, 3x venoms, 3xkabs with a blaster in each.

Ive tried to LOS him as much as possible, but even then the manticores just shred stuff.

what detachments is he using exactly? he can only use 1 formation per detachment
also the scions could always disembark after the valkyrie moved, the stratagem only prevents them from dieing on a roll of 1, but they still have to set up more than 9" away from enemies
what guns does he ususally use on the russes?
old grudges and overlapping fields of f only work against a single unit so you have to sacrifice one unit per turn
russes are slow and we are fast, try to get them tied in close combat, even if he falls back, he has to move and cant shoot
what point limit do you play?
maybe use something like wyches and tie his infatry squads down
when theyre done with them, charge the tanks
he has to be close together to make use of his tricks so multi assaulting would work

Red grief reavers will have little trouble tying up his tanks in melee. Punch a hole through the guardsmen screen and then charge in the reavers, should be doable turn one unless your opponent is really good at screening his tanks.

He uses 3 detachments, 2x battalion, and 1 scion patrol. He has a tempestor prime as HQ for the scions, with the WT that prevents guys from dying during disembark (also from vigilus i think).

With regards to old grudges and overlapping fields of fire, you actually end up losing two units. For instance, when i ran my talos, he pops grudges on one squad, and uses OFoF on the other (after he wounds a talos). The tank commanders usually just give each other re-roll turret shots + double shoot (he usually runs cadia). So unless i get really lucky with my saves, he can do some serious damage to all the talos.

But yea, i'll try a list that Skullbonz posted recently--basically just spam 8-9 venoms, and run it down mid.

what guns does he use on the tank commanders? battle cannons, punishers, demolishers? and do they have lascannon sponsons?

Battle cannons on all tanks. Sometimes he'll give 2x TC the plasma cannons. Yup they have the hull mounted lascannons, and heavy bolter spons.

maybe you shouldnt try to tank the shots and instead drown him in bodies