Competitive Tourney List Critique?

So am going to a 1750 tournament in 3 weeks, with unheard of prize support(total is over $1000). Obviously I want to try to do well, so will be bringing a competitive list! I traded my Grey Knights away about two months ago, but have the models to run the following list, which I have playtested and really enjoyed

Imperial Guard w/ Space Puppies
HQ
Lord Commissar: Melta Bombs


Marbo


Platoon Command: Chimera
5x10 Guardsmen Squads: Autocannon, Plasma, 1 Meltabomb          
Veteran Squad: 2 Flamers                                                                      


Vendetta          
Vendetta          


Leman Russ Battle Tank: Camo Netting                 
Leman Russ Battle Tank: Camo Netting                 
Manticore: Camo Netting          
Aegis Line: Quad Gun                      

Rune Priest                      
5 Grey Hunters: Flamer                           


The Guard squads form a blob with the Lord Commissar and Rune Priest attached, behind the Aegis.

So anywho, the tanks, Manticore, and IG go behind the Aegis, all the tanks getting a 3+.

Vet squad with flamers goes in a 'Detta, teams up with Marbo to kick people off of objectives.

When I played this against my friend the other day it was incredibly successful, even when my Manticore scattered 12" back onto itself. Played with a second time against a Marine gun line and won even though my Manticore only ever fired one shot, which twice scattered off target.

The blob with 5 x twin-linked autocannons and 5 x twin-linked plasma guns are able to neutralize virtually any threat close by thanks to the Rune Priest's divination psychic power, who also is great for deny the witch and ATSKNF.

Possible weaknesses? Thoughts? Comments? Violent Reactions?