Have you ever looked at a real radar screen?
You can track a CSG with a navigational radar.
You can have 1000 different radar systems going and seeing every single ship and boat underway, it makes no difference if you can’t identify the difference between a group of missile boats or a group of fishing boats.
So sure the CSG might know you’re there as far as seeing a contact on a radar screen, but that doesn’t mean they’ll know what you are.
If you emit one whiff of a known military radar, they will know what you are.
If you launch without such, the IR bloom will reveal you and get you deleted.
And if you think that the airborne radars will not see a group of a dozen ships all moving towards the carrier in any approximation of a formation, well, you need to think again.
What do you think it is?
Publicly SM2 is listed at 40-92miles.
But again, even if it was a minimum range of 25 miles, by the time the launch is detected, and the SM2 launched the missile would likely be within its minimum range.
Booster burns out after about 5 seconds. Let's be rude and assume it takes 3 more seconds for an SM2 to get turned over and pointed at the incoming, this is after about 2 seconds of sustainer burn. 8 seconds total time from "Vampire, Vampire, missile launch detected." SM2 still has something like 38 seconds of burn time on the sustainer, and hasn't reached max speed yet.
How fast is your incoming missile? Let's be evil and assume it's coming in at 1km/s, Mach 2.9. A launch at 25mi is ~40km, so your missile is 40 seconds out. 10 seconds from detection of your SSM launch to SM2 launch because Aegis was not in Full Auto, but required manual launch command. Your missile is now 30km out. SM2 launches and takes ~8 sec from launch to point at the incoming. Your missile is now 22km out, and I'll be generous to your assumptions and say that the SM2 is still directly over the ship. It won't be, but it makes for the
longest "minimum range" calculation. The first SM2 will impact your first AShM in ~10 seconds, at a range of about 10km. (In all likelihood, that impact will be in ~5 seconds at about the same range due to the booster shoving the missile towards the incoming for several km as it accelerates past Mach 1 and has a top speed of well over M2.9)
And this is assuming 1) that the Aegis system isn't in full auto, so requires a human's slow reaction times before the first SM2 flies; and 2) that the booster needs to pretty much burn out before it points the SM2 at the target and cannot start maneuvering as soon as the stack clears the launch cell.
So, if you're lucky, you will have to get within 30km of a carrier group that is unaware of you in order to launch current top-end AShMs like SS-N-27 Kalibr.
If your AShMs are subsonic, well, the range at which the booster burns out on an SM2 is about 2km. And I think the closest anyone wants to be to a 500kg blast-frag warhead going off is about 2km. So you might have to get within 5km of the Aegis ships to get that missile within the minimum range of SM2s if Aegis is in full auto.