[Endoperez]

The nations specialize. Middle-Age (MA) Marignon, as an example, is a Fire/Astral nation with a touch of other paths I don't remember. Other nations have different magics. Pretenders don't affect the mages available. Gem income is often just as important as the power of your mages.

As far as magic power goes:
1 is low
2 is base power: fireballs, bolts of lightning, etc
3 allows most good stuff, most often
4 is high, and all paths have at least one booster item available at level 4 and construction 4 or 6.
5 and above is for the heroes, pretenders and epic spells, and mages that start with 5 or more can also use booster items and spells to reach most high-level goals.
9 and above is only used for spesific strategies, to reach spesific goals. Pretenders rarely take magic over level 5 or so unless the nation can also use the bless it provides.

Example with Marignon:
Their Grand Masters can get up to Fire 4 or Astral 3 with a lucky random pick (click on the question mark next to the magic paths to see what they can get). With that and research in Construction they can forge a Flaming Helmet or a Starshine Skullcap, bringing them to Fire 5 or Astral 4. The Conjuration spells "Phoenix Power", "Light of the Northern Star" and "Power of the Spheres" can be used to further increase their paths to Fire 7 and Astral 6, for battles at least.