Can you clarify on that? I've not seen raptors yet. Hang the main fleet out on the AI planet somewhere and raid the guardposts with the raptors?
If you mean attacking the AI turret ball with the main fleet, won't it take out the guard station there anyhow?
Dropping the main fleet on the AI planet serves two purposes: One, and probably most importantly, it takes up tractor beam space so that the raptors can slip by. Raptors are fast but flimsy. The main fleet is also there to distract sniper shots. When you're going onto a planet with dozens (or more) of sniper turrets, they tend to chew through your raptor fleet fairly quickly. Once the raptors are through, you can get them to raid around the rest of the planet, and not just the guard station on the wormhole, if there is one.
I didn't realize how bloody amazing raptors were until I decided to raid a core world. The planet had five data centers, ten guard posts, a spec ops post and two warp gates. A lot of objectives, and I'd already put the planet on alert to gain a Z generator. I was preparing for a hell of a slog of repeated raids and repeated rebuildings of my fleet to get them all. I dropped the entire fleet on the planet and began to divide my forces among different targets. When I unpaused the raptors blew past everything in my fleet, everything in the AI's fleet and killed their first objective before anything else got started. Before my raptor fleet bit the dust it had killed eight of the ten guard posts and four of the five data centers. I couldn't stop laughing.