Barclay was a Rank 2 Magus, a middle-aged man in his thirties. Being able to become a Grade 2 Herbalist at such a young age naturally birthed an arrogant nature in him.
For the three major professions, the Grade corresponded with the Rank.
Meaning, a Grade 1 Herbalist could concoct potions useful for a Rank 1 Magus. Similarly, a Grade 2 Herbalist could concoct potions useful for a Rank 2 Magus and below.
The reason why professions were divided into Grades was that each grade had a mana requirement corresponding to a Magus's Rank.
A Grade 1 Herbalist couldn't concoct the same potion that a Grade 2 Herbalist could because the former wouldn't have that much mana available to begin with.
However, mana wasn't the only requirement for becoming a Grade 1 Herbalist, let alone a Grade 2.
A Magus needed to have vast medicinal knowledge and decades of practical experience to even become a Grade 1 Herbalist.
