I have an idea which might surprise a few IG opponents. Must have the first turn/enemy must not sieze the initiative for this to work.
First, take Creed an HQ. Second, get 6 Ogryn with a Chimera transport and deploy them inside the Chimera. Chimera should me deployed right up against the 12" deployment line WITH THE REAR HATCH FACING THE ENEMY.
Now, grant the Chimera a Scout move using Creed's Tactical Genius rule.... move the Chimera 12" toward the enemy so that is just over 12" away (back hatch still facing the enemy). Scout move over. Now Turn 1 begins. Disembark Ogryn so they are 2" away from the Chimera's access point, making them just over 10" away from the enemy deployment zone. Next, do their normal 6" move, taking them to within just over 4" of the enemy deployment zone.
Finally, have them charge any enemy vehicle/unit that is deployed along the enemy deployment zone. That is 25 S6 attacks. Against a vehicle, it will hit the rear armor (usually AV 10) and all 25 attacks will hit, since the vehicle has not moved yet.... high chance of destroying the vehicle. Against enemy infantry, you can shoot first (18 BS3 S5 shots can at least inflict a few wounds) and then charge with the 25 S6 attacks. This is especially effective against powerful enemy units that you want to tie up for a couple of turns so they cannot move toward your gun line (i.e. Ork Nob Bikerz, Seer Councils, Nid Warriors, Necron Immortals, Harlequins, Bezerkers, etc.)
Perhaps most important is the psychological impact. What player expects to be charged on turn 1 by Imperial Guard? Much less by Ogryn!
Can kind of throw their plans in disarray and give your gunline time to sit tight and blow everything away from long-distance in true "Hammer of the Emperor" style