Scenario: A rather isolated imperial world is hit with a tiberium meteorite in order to terraform it to the Scrin's liking. Much like in the C&C Earth scenario, a sleeping Scrin force waits hidden in an asteroid field for the right time to harvest the tiberium and wipe out the natives.
Due to some warp anomaly of some sort, the tiberium expands across the planet quicker than normal leaving 50 percent of the planet blue zones, 40 percent yellow zones and 5 percent red zones(with the other 5 percent still unaffected) within a matter of months, by which time a large force of the Astra Militarum(or Imperial Guard if you prefer) have arrived to maintain order. Due to their efforts however, an explosion is set off large enough to attract the Scrin. A few months later the Scrin force arrives(as the planet has nor orbital defenses or ships at the time) and begin harvesting tiberium and engaging in full scale war with the Imperial Guard. Space Marines have been notified, but no one knows how long it will take them to arrive.
In this particular battle, a large force of the scrin will attempt to wipe out a major industrial city on the world that is being defended by a large Imperial Guard force.
The Imperial Guard is a Cadian regiment.
Scrin Order of Battle
Command: Mastermind x1
Tech Support: Assimilator x10
Main Infantry: Buzzer Swarm x100, Disintegrator x500
Heavy Infantry: Shock Trooper x120
Recon: Ravager x90
Medium Vehicle: Gun Walker x50
CQC Vehicle: Corrupter x20
Anti-Air Vehicle: Seeker x20
Main Armor: Devourer Tank x30
Heavy Armor: Annihilator Tripod x10
Artillery: Devastator Warship x3
Main Air Support: Stormrider x10
Heavy Air Support: Planetary Assault Carrier x2
Anti-Infantry Defense: Buzzer Hive x10
Anti-Vehicle Defense: Photon Cannon x5
Anti-Air Defense: Plasma Missile Battery x5
Heavy Defense: Storm Column x3
Mega Unit: Eradicator Hexapod x1, Mothership x1
Superweapon: Rift Generator x1
Note: The Scrin units are all fully upgraded and the defenses are at a small base set up in case their forces need to fall back. They have enough reactors to support their structures, but just barely.
Imperial Guard Order of Battle
Commander: General x1, Commissar x1, Priest x1, Psyker x1
Tech Support: Techpriest Enginseer x5
Main Infantry: Guardsmen x1200(divided into 30 platoons; each platoon has a command squad with a lieutenant with a powerfist and plasma pistol, two guardsmen with lasguns, and a commissar with powersword and laspistol. Each platoon also has three heavy weapon teams including one heavy stubber team, one missile launcher team, and one mortar team. Each platoon also has three guardsmen squads, each consisting of one sergeant with a chainsword and bolt pistol, seven guardsmen with lasguns, one guardsmen with a grenade launcher, and one guardsmen with a meltagun).
Heavy Infantry: Ogryns x50, Kasrkin x50
Recon: Sentinel x50(each with a multilaser)
Medium Vehicle: Chimera x50
CQC Vehicle: Hellhound x20
Anti-Air Vehicle: Hydra Flak Tank x20
Main Armor: Leman Russ Battle Tank x30
Heavy Armor: Baneblade x10
Artillery: Basilisk x6, Wyvern x2, Manticore x2
Main Air Support: Valkyrie x10
Heavy Air Support: Marauder Bomber x5
-note that IG air assets may not leave the atmosphere.
Anti-Infantry Defense: Heavy Bolter Team x5, Autocannon Team x5
Anti-Vehicle Defense: Missile Launcher Team x10
Anti-Air Defense: Missile Launcher Team with flak missiles x10
Heavy Defense: Lascannon Team x3
Mega Unit: Warhound Titan x1
Superweapon: Deathstrike Missile Launcher x1