[@Vhagar] I'm not a GM but here's my thoughts on your question:

For the weapon, just use a halberd or a glaive, they're basically the same thing as a naginata in essence and double ended glaives are  both a bit too far out there for ES and realistically less practical than one might think

For background I'm going to wager its just like a bio of their life and how they ended up in a mercenary company. Remember, you don't need to be a fighter to be in a mercenary corp or have the highest tier skills and equipment. There needs to be a support staff like smiths, logistics peoples, etc, basically civilians or people who can't fight quite as well as the actual mercs themselves. Merc companies are basically businesses, you can't have a business by only hiring one type of employee.