I'm new too, and I think I'll have to try this out. It seems perfectly feasible to me, and it would likely be a nice precursor to a larger invasion...or simply a distraction intended to keep your enemies chasing your Arcovas to one end of their empire while your mass your fleet at the other.

The most sophisticated "task force" tactic that I've seen the AI use is really nothing more than an obnoxious, if effective, delay tactic. When you launch your main fleet away from a planet, they'll send in small groups of Purge bombers, or what have you, and cause all sorts of annoyances behind your lines. If you're playing on a map with long phase lines, this can be particularly annoying, as your response time will be greatly slowed.

But I have yet to see the AI use a small task force of Arcovas. Sounds feasible to me, although later on in the game it would be easily countered, assuming your enemy had a healthy economy. As I said, a nice precursor to an assault, or an effective distraction. Sounds viable to me.