Sounds like a very clunky play style..........so you will hit with the dual wield , then 2 handed sword.......then you hammer of the ancients ?the Walking Arsenal if I recall correctly, requires you to have damaged with single handed, dual wielded and double handed weapons for it to be ACTIVE
above your EXPERIENCE flow bar you will see when they are active and thus, gain that bonus
One thing I hate about D4 is the resource generation. So much emphasis on it. Died so many times because I had to generate resource then attack with main skill. I know it was in D3 too, but it did not feel that bad to play. Maybe it gets better late game ?