Levels and Ranks
As a rule of thumb, "one advance per level" gives virtually the same result as the official conversion guidelines, and is easier to remember when converting existing characters.
Official level conversion:
In practice, both should work equally well.
There is a lot of good stuff in Beasts & Barbarians that canbe useful in a fantasy game. Included Edges:
- Armor Training ("Hoplite Training")
- Ace (revised)
The rules for two and single player campaigns ("Heroic Duo" and "Lone Wolf") will probably used for fantasy campaigns.