AI and selecting targets in a fleet.

Attack / (Defense + HP), where Atlas modules add a large multiplicative modifier onto the ships they apply to.

I don't know the value exactly that an Atlas module multiplies it by, but ~500 is probably a safe bet, for 500 * Attack / (Defense + HP).

So if a ship has no attack but Atlas modules that give bonuses to the fleet it will not be attacked untill all the fighters are dead.  Is it benifical to add fleet support ships like this to a fleet, or is it better just to add another fighter?  What do most people do?

In DA there are 3 ways i will structure a fleet.... if the AI is using powerful fleets then i will use tiny hulled ships backed by military starbases. If i am going to take losses one way or the other, then at least they should be cheap losses! I will remain on a defensive stance untill my technology pulls its finger out. Also along this same line i may also choose to throw in some more powerful ships to gain experience while the tiny hulls do most of the fighting and all of the dying..... once again, if i have to take losses, they may as well be cheap losses!!

Now if i can get a powerful ship with enough defence to withstand enemy firepower, i may choose to fill the fleet with the same or, if i don't have enough ships yet, i may as well fill the logistics with tiny hulled ships that have reduced firepower so they are not targeted first.