Not really... Just coordinate a couple attacks at once more then one is harder to defend.

You can still have subs, and you can still coordinate joint attacks. You just wouldn't be attacking the same structure.

I think this is great. UAC has a sub, but it is a training sub. Even if we could we wouldn't allow them to attack the same colony as us. This will really cut back on sub abuse... And yes I believe there is a difference between having a sub and abusing subs.

yea not the greatest idea today me and an ally attacked a noob at the same time and he made me lose a bunch of troops so it really isnt a good idea unless they make it so alliance rules apply to those marked as ally