I have found this to be uncommon but there will be mods out there that are not compatible with this mod.

Specifically this means that no matter what order you place a Fleet Formation Mod in your Mod list, it will not work correctly and the ships will be too spread out.

As I become aware of these mods I will list them here.

Note: These ships come with a built in Fleet arrangement or add trails to ships. These mods are not compatible with the "Fleet Formation Mods" or any other mod that changes the arrangement of the ships in a fleet or removes trails.

Star Wars: Kuat Ancient Empire
Stargate - Shipsets NSC3 Patches
Stargate - Asgard Shipset
Stargate - Goa'uld Shipset
Stargate - Lantean Shipset
Stargate - Ori Shipset
Stargate - Tauri Shipset
Stargate - Wraith Shipset
Asura's wrath ships
Federation Builders: Ships and Cities
Cheek's Federation Builders - NSC3 Patch

Partially Compatible:

Gigastructures is partially compatible with the "Fleet Formation Mod v2" when creating a fleet with ships and an attack moon.

The reasons Gigastructures is partially compatible are:
1. Gigastructures is coded to have a fleet of ships spread out more when grouped with an Attack Moon.
2. If the attack moon is destroyed or if the attack moon is taken out of the fleet, the fleet stays spread out.
3. Other Gigastructure ship types may encounter this issue if ship spacing is hard coded.
4. To restore the fleet formation to have the ships closer together again you have to reform the fleet into a new one.

Note : I did not see any issues with fleet combat due to the fleet spreading out around an Attack Moon. It is personal preference as to whether this is acceptable to you.

**A compatibility patch may fix it**