As you could have one that can build up a nice base and another to work on the combat side of it if it does get to easy maybe have a enemy leveling system to so if you have co-op and you partner is killing the enemies too easy their level and/or pack/group grows bigger/stronger.
Also would like to see in the start of the game some maybe low level weak enemies walking around to help level up or get money by stripping them and selling their gear when I 1st started i found it very hard and long to build up hoping one of the towns got attack so I could steal the gear to sell I spent about 2 hours just roaming around trying to get gear to start up.
To end I would like to say really great game keep up the great work and looking forward to the final product