One mistake I see made far too often by players and mission creators, is that the ships in a formation are spaced far too tightly. I know it is tempting to have all your pretty ships nice and close to each other where all weapons could be brought to bear on a single target. I know it is tempting to use the default 10nmi radius for your formation. However, I'm here to tell you why this is bad.

Introducing: the survivability onion!

When you place all your ships in a tight formation, you are effectively putting all your eggs into the "don't be hit" basket. If you are detected, any weapon launched at you will be targeted at the big, juicy carrier at the center of your formation. If even a single weapon gets through your air defenses, it will hit that very squishy and valuable carrier. And as most of you will have experienced, air defenses in this game are not impenetrable.

Don't Be Identified/Acquired
As you'll probably know, EMCON is part of this layer of the onion, but so are your escorts. If your outer layer of escorts are far enough out from the carrier, they might be able to deter enemy aircraft, submarines or surface units from getting within sensor range of the carrier, even if the escort itself is detected, thus keeping the carrier safe.

Don't Be Engaged
A widely spaced out escort also means that an attacker has to get much closer to or even penetrate the outer ring of escorts in order to launch an attack on the carrier, consequently putting itself at greater risk of detection or counterattack before it is able to launch.

Image from Modern Naval Warfare by David & Chris Miller

Don't Be Hit/Penetrated
If, despite your previous efforts, an attacker has managed to launch an attack, a widely spaced escort gives you more time and space to intercept the weapon before it hits the carrier. For example: the SM-1MR has a max range of (almost) 25nmi. With a 5nmi radius on the escort, this means you'll start trying to intercept it 30nmi from the carrier. If you instead have an escort with a 25nmi radius, you'll start trying to intercept it 50nmi from the carrier. Also remember that with mid-long range SAMs, it is possible to have mutual support without every ship having to be within CIWS range of each other. As per above, two SM-1-armed ships can still somewhat cover each other even if 15nmi apart from each other.

Furthermore, it is also possible that an attacker is forced to target one of the escorts instead of the carrier and a frigate is far more expendable than the carrier it is protecting.

Image from Modern Naval Warfare by David & Chris Miller

Look at this Kirov, isn't it scary?

As some of you may have experienced, the P-500 and P-700 (NATO reporting names SS-N-12 Sandbox and SS-N-19 Shipwreck) differ from other anti-ship missiles in one very important way. They are datalinked and able to share targeting information between each other. Half of the salvo will go after the largest target they can spot, while the other half go after other targets. This means two things:

1. If your escorts are close to the carrier, the missiles will be able to see and target said carrier.

2. The missiles will also be able to spot multiple targets, meaning you could end up losing several ships to one salvo, whereas a more loosely spaced formation could mean the missiles all aggro onto a single "missile sponge".

Ryu1940 on Youtube has an excellent video about this concept.

Image from Modern Naval Warfare by David & Chris Miller
Note the multi-layered defenses and the distances involved.

While this may not be entirely relevant for the game itself, I've chosen to include it anyway for the sake of historical context.

The Cold War is commonly associated with nuclear weapons, and at sea things were no different. A number of weapons represented in this game were capable of carrying nuclear warheads. The A-6 Intruder, deployed on US carriers, could carry nuclear bombs, while a number of Soviet anti-ship missiles such as the P-35 (SS-N-3B), P-500 (SS-N-12) and P-700 (SS-N19) missiles could also be equpped with nuclear warheads. Additionally, both the United States and Soviet Union would develop nuclear torpedoes such as the Mark 45 and T-5/Type 53-58, which could be launched from submarines.

Needless to say, you would (presumably) not want launch platforms carrying such weapons to get a good fix on your carrier.

The "historically accurate" Battlegroup Echo, available in the mission editor. Note the 40-50nmi radius on the outer ring of escorts.

In conclusion: space your escorts out. Don't just pile them all up on top of the carrier. The escort is there to prevent the carrier being shot at in the first place, not just to intercept missiles targeted at the carrier.