It doesn't matter how many characters they add if they don't get their priorities in orders.
First of all, they need to allocate their time and money wisely, drop this huge art style crap and do some abit more budget conscious and focus less on looks and more on making complete, useful characters. In XII you have characters like Ash, Terry, Iori, Kyo, and Joe who perfectly built. The you have Athena, Kim, Daimon, and Benimaru who are ok but need a bit more work, then you have Kensou, Mature, Clark and Elizabeth who are severely butchered and lacking. Matureand Clark suffering the worst, but Kensou and Elizabeth are just lacking and Elizabeth especially needs work cause in XII she glitchy with having about two atttacks that stop working when she has a full critical counter gauge. Then you have Shen Woo who has all his moves just about, but then he has all then extra follow ups that I have never seen anyone even bother trying to use because simply refuse to come out. Leona and Ralf are just different for the sake of being different in Leona's case its a change that works, but in Ralf's case they made him like a Kevin Rian rip off.
They need to revamp the characters and make them play in a way that is more usefu and true to the characters. Second of all they need to go back to using character themes, the music they have for XII is terrible. It is by far one of the least satisfying snk soundtracks I have ever listened to. The gamd stages also needed to be toned down in terms of distractions such as the crowds of worshipers in the Egypt stage. They need to also make changes to the system.
System Changes I'd like to see:
Removal of CCs: They aren't really all that useful and turn the game into a mash C till a counter hit lands. Then you have to do a few very specific combos to get the most damage out of the meter or just spam the same special attack. Its a Gimmick that is pretty useless.
Redo Clashing/Deadlock system: I understand that they wanted to make the game abit more free in terms of how to handle attacks meeting attacks, but the clashing system is too free with a simple punch clashing with a projectile and attacks that should trade instead clashing arbitrarily. It needs to be tightened up.
Changes throws back to one button: KoF just worked better with one button throws and this change happening is just because its in SF4. SNK needs to stop basing some of its mechanics decisions on what is in other games.