I seem to play GF a bit differently than most in the sense that my combat style mixes the classes.
My Agent relies on melee more than magic, but uses magic for tough battles. And, of course, my Agent always has two Drayks with her. This works well for me, and I usually end up stronger than if I made a magic based Agent.
My Shaper is able to fight for her/himself, and is not reliant on the creations, though I always have a small pack following me around. My Shapers primary attack is melee, and magic is secondary. This has also worked very well for me.
So, IMO, I'd like to keep the spells I'm familiar with open to all classes rather than specialized, as it restricts the player to more linier character choices.