Another important point...
Don't forget that a lot of the archer's special abilities don't work beyond 30 feet, and that most enemies at 16th level can close that distance in one round... Thus, the archer has to stay at longer range, losing some of his abilities AND suffering minuses to hit (due to range), or else suffer attacks of opportunity when the enemy gets close (or switch to melee). If he takes the latter choice, he will be weaker than Mr. Melee, due to his choices of Feats.
Now while the longbow may not have the range problem so badly, the loss of some abilities beyond 30 feet still affects (ManyShot can't be used, for instance). If Mr. Archer gets close enough to use it, he can be closed with and must either melee (with fewer Feats helping), or suffer AoO while shooting at his enemy, or move, lose attacks, and shoot twice (lowering damage). He probably also has lower AC.
If you want to weaken archers (as Seasong's analysis shows), don't allow Enhancement Bonuses to stack. That's the easiest fix.
As for Mr. Melle, if you don't mind a 1e fix, Bracers of Melee: As Bracers of Defense (Armor, in 3e), plus, three times/day, allows any Fighter/Paladin/Ranger to double the number of attacks in one round. (In 3e this is probably too powerful - it should probably add ONE attack/round at the highest BAB, instead!)
Those "fixes" should more than balance Mr. Melee (unless you let the Bracers of the Blinding Strike also apply to missile attacks).
Don't forget that a lot of the archer's special abilities don't work beyond 30 feet, and that most enemies at 16th level can close that distance in one round... Thus, the archer has to stay at longer range, losing some of his abilities AND suffering minuses to hit (due to range), or else suffer attacks of opportunity when the enemy gets close (or switch to melee). If he takes the latter choice, he will be weaker than Mr. Melee, due to his choices of Feats.
Now while the longbow may not have the range problem so badly, the loss of some abilities beyond 30 feet still affects (ManyShot can't be used, for instance). If Mr. Archer gets close enough to use it, he can be closed with and must either melee (with fewer Feats helping), or suffer AoO while shooting at his enemy, or move, lose attacks, and shoot twice (lowering damage). He probably also has lower AC.
If you want to weaken archers (as Seasong's analysis shows), don't allow Enhancement Bonuses to stack. That's the easiest fix.
As for Mr. Melle, if you don't mind a 1e fix, Bracers of Melee: As Bracers of Defense (Armor, in 3e), plus, three times/day, allows any Fighter/Paladin/Ranger to double the number of attacks in one round. (In 3e this is probably too powerful - it should probably add ONE attack/round at the highest BAB, instead!)
Those "fixes" should more than balance Mr. Melee (unless you let the Bracers of the Blinding Strike also apply to missile attacks).