Well now. Who would even replace him if this is true? Does it come down to wanting some utility that other spear users may have?
Ma'curi is pretty much a glass cannon while Djugen has multiple defensive skills and buffs that would also boost other spear users (negate circle, augment circle)
I imagine you could build a pretty kick-ass spear team with Kem and Djugen that would completely ignore the rock, paper, scissor dynamic of the weapons.