For a long term perspective, its fine. They can bring very specific combinations in the future expansions. Example: one expansion can with more 4 hybrid classes like: warrior <-> healer / scout <-> mage and a second expansion with warrior <-> scout / healer <-> mage combinations.

Yeah, I think that'd feel a bit more balanced, rather than the dichotomous/reciprocative approach that they're using. Maybe would've seen a nice Paladin (Healer-to-Warrior) or Arcane Archer (Scout-to-Mage).

A bit sad they didn't go for a 'circle' as in: scout to healer, healer to warrior, warrior to mage, mage to scout for the hybrid classes.