I would like to be able to send fleets from multiple planets in a joint attack on pirates.
Currently I have to manually time it and send 2 fleets to attack the same pirates or planet.
There simply should be an attack option which lets you pick fleets from ALL your planets. The closest planet will be taken first. Then an overview is displayed from where the ships are send.

Example:
My Planet 1:  50 Dreadlisk; Distance to target: 1000
My Planet 2: 50 Dreadlisk, 5 Devourer; Distance to target: 5000
My Planet 3: 50 Dreadlisk, 5 Devourer; Distance to target: 10000

Selecting the new attack option.
Example selection:
50 Dreadlisk = normal attack from the first planet on the target. Only the first planet occurs in the overview of send ships.
50 Dreadlisk, 5 Devourer = normal attack from the second planet on the target. Only the second planet occurs in the overview of send ships.
100 Dreadlisk = new joint attack from the first and second planet on the target. The first and second planet occur both in the overview of send ships with the exact amount per planet and vespene cost for all combined.
-> 2 fleet slots are reserved for this joint attack. The fleet from the second planet starts immediabtely. The fleet from the first planet will start at the moment when the second fleet need the same time like the first fleet. (Because it is impossible sometimes to do this by scaling the speed of the fleet down)
150 Dreadlisk, 10 Devourer = all are used in the attack and all are shown in the overview with combined vespene costs.
-> 3 fleet slots are reserved for this joint attack. The furthest away starts immediately, then the second when the furthest needs the same amount of time like the second and then the first when both others needs the same time like the 1st.

When aborting the joint attack then all fleets that are used in this attack are returned.
When the attack has been carried out successfully all fleets return to the planet they came from.

I like it. It would make useful the share fleet buttons for unallied players.

Haegemona, you already are capable of doing joint attacks with friends over the shareing of fleets.
This one is only about joint attacks for yourself.