You stopped waaay too soon for the fighter. Give your Fighter 3 more AC, because he's got Armor Mastery III. And some DR, because the Plate is Adamantine. Then the Fighter slips on his +5 Mithral Tower Shield. Now compare ACs. You can have the Rogue equip a shield as well, if he's proficient in their use. Is your rogue still 'better suited for melee'? Ask a Cleric and see which they would rather see in the front line....