THIS CHEAT WILL ONLY WORK IF YOU HAVE TWO FINAL FANTASY A2 GAMES TWO TRADE WITH!!!
This cheat is mildly confusing and might take a while to understand it.
Okay... we'll refer to the games as Game1 and Game2.
First, on Game1, you must save your file over both files of the game. Next, you must go to the trade menu and trade your 'will be' duplicate (we'll call him Al) to Game2 for a clan member from Game2 that you never use. Notice: IF YOU CHOOSE TO TRADE IN THE FUTURE, YOUR CLAN MEMBER FROM GAME2 WILL BE LOST FOREVER!!! Once you have traded, go out of the trade menu. On Game1, switch files to the one that still has Al. Do you notice that you now have your Al on Game2 and still on Game1?! Okay, then you trade from Game1 someone you never use to Game2 for Al. And, lo and behold, you now have 2 Al's on Game1!!!
REMEMBER:YOU WILL LOSE THE FIRST CLAN MEMBER YOU TRADED IF YOU DUPLICATE IN THE FUTURE!!!

Don't blame me if you don't understand, I did my best to make it clear.