When i use the option to remove the ships guns (on the enemy), i find that it will only work if you can see the little greyed-out pictures of the enemy ships, the ones you need to click on to be able to destroy the ships, which leads me to my 2 problems:
1. it is very infrequent when i can see a fleet that has the greyed-out pictures when i click on it.
2. I have no idea what causes them to be seen. i treid placing a spy on a ship, but i dont think it helps.