It's the only thing I can think of because DQ was one of the first games where selecting your gender was a thing. Like I said, just feels like a huge missed opportunity.
This is the only tiny string of hope that has me hope for an Echo, Not so much to give a twist on the moveset, but to provide more alts to the "Hero". Hell, THe Final smash could be the exact same but have the prominent females take the place of the MCs.
Speaking of, who would be the fourth? I figure Anlucia, FemErdrick and FemSolo for sure, but with out going into Spinoffs, I can't think of another (Outside of the Daughter in DQV, but the height difference is absolutely apparent.) Tagline could be the other of the Obvious DQ staples, "Heroine joins the party!"