From my experience with RDM so far I would say that a buffed RDM (temper, haste 2, enspell) is about equal to an unbuffed MNK. I don't have the tools to test this theory numerically so this is just from my experience using both jobs for various solo activities (dynamis, salvage, meriting, etc). Now from a solo perspective this is very well balanced. However in parties the gap widens considerably, imo to the point where RDM in melee is no longer worthwhile, given the fact that the Monk gains further outside buffs while the Red Mage is pretty much still limited to only what he can cast on himself. The reason you are seeing only a small gap on Wopket is because Wopket is vulnerable to slashing damage, hence why SAMs completely destroy him, so this really can't be used as a valid example of RDM melee prowess.

To be fair I'm not extremely displeased with RDMs melee capability. I'm more upset with the mindset of the majority of players who refuse to allow RDMs to even try to melee. So far I've only made 2 or 3 suggestions to improve RDMs melee capability, and they are all very minor changes: A- sword skill, Improved En-spells, and Bravery. And all I've received so far is aggressive opposition from virtually everyone.