This keeps the rich features of a Season type without requiring constant string parsing (as much) or going through World to do lookups to get the objects. Since seasons now have value equality instead of reference equality, it's easier to get access to whem when needed. They're still, fundamentally, sugar over a tuple.
There are probably still reference equality issues here since Unit still has Season and Power objects. The test case builder also still works on reference equality in some places so the second part of adjudication is broken.