Already have PD (2 x evolve, 10/10, 198) and Michael (1x evolve, 9/10, 193) is it worth working on athene to replace either of these?
It depends on the game mode. If you need PD for something, no one can ever replace him.
However, I think it's a moot point in the end. Athena is definitely worth working on. It will not be a waste of resources or time, at all.