I believe that designing the fight considering 2 melee is the thing that guarantees the most fairness to the free spot in the party.

In EW, with the fact that melee have clearly been advantaged with huge hitboxes + reduction of positional (and combo interruption), that has reduced the expression of personal ability in maintaining uptime so much, as to actually make it much more convenient to bring, in the free spot, a melee instead of a caster or a prange.

With the new content, and with yoshi-p's statements, I expect that in the free spot it will no longer be *clearly* convenient to bring a melee into a midcore prog-clear static or in pf.