Act 3 Re-Spec into Throwzerker?

As the title says, just reached Act 3 and a member in our party who's built a Fighter Barb to this point wants to transition into a Throwzerker build. We don't have too much in terms of throwing based gear (basically just Ring of Flinging). We got the Dwarven Thrower and we plan on getting Nyrulna.

How should he got about a re-spec at this point, given the current lack of optimized gear? We're Level 10. I did see the "Honor Mode TB Throw" guide attached, is that the best route to go? He wanted to Throw in Act 1 but we killed the goblin with the Returning Spear and progressed too far before realizing that was the only Act 1/2 option for a Returning weapon hahaha

Another question, if he wanted to alternate throwing Dwarven Thrower and Nyrulna, I know you can throw a weapon from your inventory and it will still return. Could he in theory have a main melee weapon, and still be able to cycle throwing those two, and it will keep his main melee equipped? Or is it better to do a class where he can dual wield and have both equipped? Appreciate any insights or recommendations!