I had a chat with some people and found out a few priority spots for pickpoints for these two skills.

MAGES:
Mages spells are strongest when they have high rationality, so have Reasoning and Will high.
With high reason and will, the spells are stronger and you will also learn quickly. The will attribute also adds to your life total and the Reason attribute will help you score a hit.

SUMMONER:
Summoners monsters are most effective when you have alot of charm, so have Instinct and Vitality high.
The instinct also helps you dodge some and the vitality helps to soak damage.
You may also find it useful to get to be a good enough with magic to remote heal or heal summon to heal your creatures a significant amount.

EMU:
For both of these, ingredients are very important, so some Physique and Coordination will be required. For the summoner, this will get to be less important later on, since you will eventually get to make summoning stones.

I started out a character called Of_The_Fang to test out the idea of coordination+will+vitality for the only attributes.

I have not spent too much time on it, but I think this might be a valid combo for summoners, mages and perhaps even fighters.

At this time, equal portions of those attributes are recommended. I am not sure if a person should have a different ratio when the character is rather new or not.