This reminded of some times when the Tywom are in the game I'm playing, and they have a lot more moves than I do. They didn't have as much as you are seeing, but it was more than I expected. I decided to see if I could find a reason. This is what I found.
Base moves of all ships = 1
Hyperdrive = +1 (the game designs all ships with at least one hyperdrive)
Tywom = +2 (They have the Fast +2 trait that gives 2 extra moves)
Their base is 4 moves.
All difficulty levels above Normal = +1
Their base is now 5 moves for difficulty levels above Normal
All difficulty levels above Normal also have extra bonuses that are a percent increase.
Gifted = +33%
Genius = +200%
Incredible = +200%
Their final base moves are:
Gifted = 5 + 33% = 5 + 1.65 = 6.65 (I think this rounds up to 7)
Genius = 5 + 200% = 5 + 10 = 15 (less than what you're seeing, but I think I can explain it in next section)
Incredible = Genius
The Tywom have a colonizable planet in their starting system. The AI usually rushes a colony ship and settles a planet like that in the first few turns. They then have to choose a government. If they choose Imperial, they get an extra move.
If this is the case, then their final moves will be 8 for Gifted and 18 for the other two.
If this is the case, it will explain why I'm see Tywom ships with 8 moves and you're seeing one with 18 moves.
I'm beginning to hate them more than I did before I did this investigation.
