Combat class generate nearly 0 gils (the repair cost are still too high compared to gil dropped and time spent).
Combat class get 0 loot to sell in market. Crafting component from AK are worthless in market since you can drop them outside anyway. All drop are BoP/Unique and cannot be converted to materia.

Crafter can generate gil with leves (3 to 9 times more than combat class)
Crafter can sell items in market (not sure it will last)

I guess there is no problem !