ELI5: Do exp penalty’s get transferred to the group?

[Tecmos Deception]

Just doing my usual devil's advocate thing here: the example of 16 and 20? The warrior is only like 10% more exp than the SK but by being both a warrior AND 4 levels higher, will be a monstrously stronger tank. A level 15 that beats up the SK decent won't scratch the warrior, an 18 that annihilates the SK would be just another blue con for the warrior, etc.

While it's true that a level 16 has 4x as much exp as a level 10, it's not really something that comes up a lot I don't think.