From Data Realms Wiki
The Coalition are typical military cloned units. They have a extensive arsenal of weapons.
Coalition Light Soldier
A Coalition Light is highly, if not rediculously, agile and nimble. Unfortunately, the Coalition Light has severely low protection, therefore being unable to soak up as much damage as stronger, slower units do.
Coalition Heavy Soldier
A more heavily armoured soldier, better implemented as a defensive unit due to slow movement speed.
Coalition Battle Drone
A drone that generates a strong phase field around it for a surprisingly effective radial attack that can rip apart nearby units. It does not possess a jetpack but may jump. Tip: If you happen to be flying around in a drop ship picking up supplies and possibly enemy troops for extra gold, Do not try to pick up one of these drones, they will emit their pulse field and destroy your ship while you are trying to abduct them.
Coalition Medic Drone
The Coalition Medic Drone has no offensive abilities, however may heal nearby units. It is quite useful on the frontier, and is quite swift. Like all drones, the Coalition Medic Drone may not use jets.
Coalition Brain Robot
A heavily armored robot that contains the brain in a cavity in it's chest. Tip: As big as these guys look, they are surprisingly fast when they are flying around with their jet pack. These were removed in build 24, but can be downloaded as a mod from the Cortex Command Fan Forums.