1500 drop troop friendly....

Howdy guys,
This is my current drop troop army, I was wondering if I could get some advice. I like the idea, but I am having trouble killing marines with it. Let me know what you guys think.

Doctorines:
Drop Troops
Iron discipline
Close Order Drill
Allow Special Weapon Squads
Allow Rough Riders


Senior Officer
4x guardsmen
-heavy bolter
Fire Support squad
-3x autocannon
2x Special Weapon Squads
-6x Meltaguns
2x Anti-tank Support Squad
-3x Lascannon
-3x Missile Launcher

Junior Officer
-Heavy Bolter
4x Guardsmen
Infantry Squad
-meltagun
Infantry Squad
-meltagun

Junior Officer
-Heavy Bolter
4x Guardsmen
Infantry Squad
-meltagun
Infantry Squad
-meltagun

10x Rough Riders
-Veteran Sergeant, w/Honorifica Imperials huntinlance and power weapon
-9x hunting lances

LR battletank
-hull bolter, sponson bolters, extra armor

LR battletank
-hull bolter, sponson bolters, extra armor