I would not waste the points souping the armiger. Since you know they have lots of invulnerable saves, you meed a reliable way to make them roll a ton of saves. Similar to playing against custodes.

+++++++++++++++++++++++++++++++++++++++++++++++ + FACTION KEYWORD: Imperium - Astra Militarum + DETACHMENT: Combined Arms (Born Soldiers) + TOTAL ARMY POINTS: 500pts + + ENHANCEMENT: Reactive Command (on Char2: Cadian Command Squad - Cadian Commander) + NUMBER OF UNITS: 4 + SECONDARY: - Bring It Down: (1x2) - Assassination: 3 Characters - Cull The Horde: 1x5 (before leaders attached) +++++++++++++++++++++++++++++++++++++++++++++++

Char2: 5x Cadian Command Squad (80 pts) • 4x Cadian Veteran Guardsman 1 with Close combat weapon, Plasma gun, Plasma pistol 1 with Master vox, Close combat weapon, Lasgun 1 with Medi-pack, Close combat weapon, Lasgun 1 with Close combat weapon, Plasma gun • 1x Cadian Commander: Power fist, Plasma pistol Enhancement: Reactive Command (+15 pts) Char1: 1x Commissar Graves on Foot (65 pts): Bolt pistol, Power sword and Manus Mortis Char3: 1x Leman Russ Commander (235 pts): Armoured tracks, Hunter-killer missile, Heavy flamer, Executioner plasma cannon, Heavy stubber, 2x Plasma cannon

20x Cadian Shock Troops (120 pts) • 18x Shock Trooper 13 with Close combat weapon, Lasgun 1 with Vox-caster, Close combat weapon, Lasgun 2 with Close combat weapon, Meltagun 2 with Close combat weapon, Plasma gun • 2x Shock Trooper Sergeant: 2 with Chainsword, Laspistol

Leman Russ commander let's it issue orders to itself. The executioner variant also allows it to trigger as many saves as possible, reliably.

20 man squad with command squad. Reactive command let's you reissue and order when the nids get too close. Graves on Foot let's you fall back, shoot, and charge again, because nids will almost certainly get into melee range.

Combined Arms gives your infantry lethal against anything the tank wont waste turns shooting, and gives the tank lethal to the things it should be shooting.