I guess the biggest issue is, like you said, the COMPLETE lack of a build path for dual wielding. Scoundrel encourages single daggers for optimal damage and butt poking, while Warfare heavily encourages massive, bulky weapons that only Thor himself could logically lift.
While I know we'll never get it: A Berserker Tree. Take a few from Warfare and make a rage-based, all-in build path that rewards diving enemy lines like an idiot.
Warfare should be disciplined and focused damage. Right now it's just a chaotic mess. Give Dual Wielding a viable path and make Warfare more logical.
And honestly, just make Single Wielding have some other benefit and still cost 2 AP. For exaple: If you only have 1 weapon and no offhand, you start the turn with 1 extra AP, up from 4.
You're probably right, but do you have a source on why we wont be getting any non magic trees? Because giving warfare more variety would be great, and could allow for interesting combinations with how weapons typically perform. Something like beserker and duelist trees would make melee almost as complex as magic.