I swapped an an engaged armored fesh with a stormbunny and the Marsh gargantua attacked the armored fesh after the swap. Opportunistic assault states that it doesn't trigger on relocation abilities.
I can be wrong, but I remember something about "relocation from different source than the engaged unit"...
The engaged unit was the one that activated swap. I am very OK with this being true. But if it is, the description needs to be more clear.
