More Imperial Guard

Played some more 40K this evening. I've tried out the same list a few times in a row now. We're up to playing 750 points. Against my Space Marine opponent this list has won twice and lost once. Tonight was one of those wins and one of those losses.

List:
Senior Officer HQ w/power sword
Ratlings(5)
Imperial guard platoon. 1 Junior Officer HQ and 2 Infantry Squads. No upgrades.
Armored Fist Squad. Chimera with Multilaser and Heavy Bolter.
2 Leman russ with Lascannon and Heavy Bolter Sponsons.

This list performs fairly well. At the 750pt level there are a lot of troops on the board (40, or 35 if you just count the ratlings as stationary sniper platforms) so we can concentrate firepower pretty well. The Leman Russ are hardy. One of the wins (and the loss) they were the last of my army left on the table. The senior officer doesn't perform so well in close combat. I find myself wishing his squad was a harder hitter. My opponent has been fielding two tactical squads(one with rhino), a devastator squad, and a terminator chaplain. His power-armored goons spread across his starting line then march inexorably across the board. It's a rare day when I'm able to stop them from reaching my infantry line. The lack of counterassault in my army is causing me lots of concern. I've been perusing various sites and I think I'm going to have to ditch my chimera for some meatier hand to hand and shooty bits.

Here's my probably army list:
Senior Officer HQ
Force Weapon
2 plasma guns
Vet. Medic
2 Bolters
Iron Discipline
Commissar w/ power weapon

9 Ratlings

Infantry Platoon
Junior Officer w/power weapon & bolter
Squad
Squad

4 Storm troopers (grenadiers)
1 Veteran Sergeant w/ power weapon & bolter
2 melta guns

2 Leman Russ w/3 heavy bolters

Doctrines: Grenadiers, Ratlings, Iron Discipline, Drop Troops(its free, so why not have the option of not deploying most of my troops at game start.)

This still means I have 35 models on the field (again not including ratlings). I've given up the chimera in return for a passel of special weapons and some close combat meatiness. I'm excited to test this army out and see how it goes.