Looking at the code, the CPA post will fire if you have more than one military unit on the planet. Interestingly it is > 1, not >= 1. I presume typo.
Bear in mind that the core CPA guard post has an 800 second cooldown on that ability.
The core Raid guard post has a 200 second cooldown on its ability, and (if I'm reading this right) the resulting wave doesn't show up for about 60 seconds, where the CPA trigger is instant. Also, the Raid seems to trigger on any (non-zombie, non-minor-faction) human military ship, so you can't even sneak around with 1.