Got it. It makes sense.
But, I do believe that an AI-launched defensive snapshot option is needed as part of the doctrine. Right now, unless there is another way to do it, it appears that if you can get the first shot off against a sub, then the targeted sub will turn and run. That means that you can stay 10 kts and under and follow with impunity.
On the other hand, it does seem that if the targeted sub could simply manage to get a defensive snapshot off, the firing sub would have to break the wire and also run, thereby reducing the original shot and chance of a hit.
Regarding actual versus perception when it comes to our "game", you have to ask, how much of what we do here is based on perception? No one really knows whether the China's DF-21 missile could actually hit a moving carrier. It's never actually even been tried. Who knows whether this RIM-161E could actually destroy the DF-21 up in space because it's never been done? So, in order to model it into the game, the designer has to "fudge" the results a little. They have to assume that it would work, and if it works, they have to assume what the results would be, based on our perception.
So, if those results are based on our perceptions, then why wouldn't a defensive snapshot, which isn't really an actual known tactic, but merely a perception of one, be included since many sources (as you pointed out) discuss that specific action.
Not that I have a vote in this matter, I'm just a consumer who buys all of the products, but I would think that having an option to program an AI-launched defensive snapshot would be a nice thing to include in sub warfare because it balances things out a little bit, even if it is only a perception.