I can see how PL Devs allowed hybrids to be created to allow a sense of variety when advancing a character but what would be more interesting is, and i hav posted this in the PvP forums, variety between skills. There should be three paths of skills that can be chosen. For example, when, lets just say, you level up your mage to level 2, there is a choice between three skills: Fire Bolt, Ice Bolt, and Lightning Bolt. Okay just say the player chooses Fire Bolt. The next skill after Fire Bolt should be 'Fire Blast' which is also a fire spell that is stronger. Until, by the cap level, there is an ultimate skill that deals significant damage. This can be applied to either skill chosen and to other characters as well. That way there would be a nicer variety between players and mages could be called 'Fire mages', ' Ice mages', Lightning Mages, etc. This can also apply to other characters. Such as the warrior: it could be called a 'Rage warrior', etc. And archers, 'Sniper archers' etc. With each skill path taken there is a unique strategy.
If SpaceTime Studios even considers this they will have a lot of work to do but it will totally pay off