I know where the difficulty lies here, as I have dealt with this question in a previous situation myself.
We had two rogues (well one rogue and a fighter/rogue) that wanted to get sneak attack damage from ranged attacks (a feature exclusively for rogues when they're within 30 ft. of the opponent).
The problem is that someone needs to threaten the opponent in order to get a flanking bonus. So you still need someone on the other side with a melee weapon that is in striking distance of the opponenent.
In the case of two rogues on opposite sides of an opponent and they're both using ranged attacks, there is no flanking between them and therefore no sneak attack as well. As soon as one of them comes in striking distance with a melee weapon, the other rogue gets a flanking bonus and sneak attack damage. The one holding the melee weapon doesn't, as there is no opposing ally threatening the opponent on the opposite side. If both wield melee weapons and are in striking distance and on opposite sides of the opponent, both would get the flanking bonus and therefore the sneak attack damage.
I remember a 3.0 PrC (Peerless Archer or something like that?) that made a person wielding a bow threaten all areas within 30 ft. (at 10th level from the PrC, so it would've taken a high level character to pull that off). I've askes Wizards on at least three seperate occasions why they never converted that PrC to 3.5. They never gave any answer, but I guess they realized that this was probably just too powerful to let it return.
We had two rogues (well one rogue and a fighter/rogue) that wanted to get sneak attack damage from ranged attacks (a feature exclusively for rogues when they're within 30 ft. of the opponent).
The problem is that someone needs to threaten the opponent in order to get a flanking bonus. So you still need someone on the other side with a melee weapon that is in striking distance of the opponenent.
In the case of two rogues on opposite sides of an opponent and they're both using ranged attacks, there is no flanking between them and therefore no sneak attack as well. As soon as one of them comes in striking distance with a melee weapon, the other rogue gets a flanking bonus and sneak attack damage. The one holding the melee weapon doesn't, as there is no opposing ally threatening the opponent on the opposite side. If both wield melee weapons and are in striking distance and on opposite sides of the opponent, both would get the flanking bonus and therefore the sneak attack damage.
I remember a 3.0 PrC (Peerless Archer or something like that?) that made a person wielding a bow threaten all areas within 30 ft. (at 10th level from the PrC, so it would've taken a high level character to pull that off). I've askes Wizards on at least three seperate occasions why they never converted that PrC to 3.5. They never gave any answer, but I guess they realized that this was probably just too powerful to let it return.