Are you kidding?Single Wielding, is hard
Dual Wielding would be pretty nice. As Manga has pointed out repeatedly, the game can be programmed so that it doesn't necessarily make you any more skilled or powerful unless you know what you're doing. This would be in keeping touch with reality: holding two swords does not make a novice swordsman a master, and the chances that his having two swords would help him defeat a master is unlikely, at best. The thing about Dual Wielding in KH is that they incorporated it idiotically for KHII by making it some sort of "Super Saiyan" idea. They should recalibrate the entire system and turn Dual Wielding into a practical choice, albeit difficult to effectively use.
I hope that BBS does incorporate Dual Wielding since it would make sense, but it definitely shouldn't be brought back as some sort of "Mega Power Up Digimon-Merge-With-Friends" concept.