Well, I just started Act 2(...Normal difficulty) and decided to try a Defense Merc.
Usually, I just pick an Offensive Merc and then I'll switch to a Defense Merc in NM Act 2.
I just went to buy him a spear class weapon.
He said: "I can't use that" ... the weapon was a Brandistock
I believe I used that at one point with my Off Merc. It looks just like a Spetum.
So I concerned the "Gold" spear class weapons I found for my other Mercs(...Offensive) will transfer to my Act 2 NM Def Merc.
I think one was a Partizan; one was a Trident ? ... I ended up with on my Act 2 Mercs(...Normal)
Is the Def Merc limited to only certain Spear class weapons ?