The Minnows have Kill Mission, so you're going to have problems holding objectives. They also don't have a ton of staying power, so the list is a bit fragile. They do hit hard, though, and shooting from an enemy unit's rear arc is tasty.
Also, any close combat unit does better in a bigger unit due to defensive fire. Run a few simulated assaults with the Praetorians, see how they fare. It's TOUGH to get into assault.
The Bot armies are tough to run, as the Spider Drones don't have much staying power. You'll want to consider a few units of Contractors at the very least, and a Journeyman Bot Handler has some really, really good tools to use.