Trump didn't fire Clint because of his southern ways. He hired Brandy because of her sex appeal.
If Trump was looking for more polish in his apprentice than Clint offered, the argument upthread is valid that he would have kept Steuart over Clint when that choice was on the table. Frankly, it's kind of appalling to think that a candidate's polish would be a deciding factor in a job interview. A contributing factor, absolutely, but a deciding factor? Never. Our white collar prisons are full of very polished individuals. I'll take integrity any day.
Clint came to the first boardroom sans tie and when questioned about it by Trump he explained that he was most comfortable without it, but if Trump preferrred him to wear one, he would. And he did for the rest of the season. He chose the Liza Minnelli task to prove that he was capable of handling tasks that you might not think he necessarily could. He told Trump he was prepared to move anywhere he was needed and offered to work in Scotland where Trump currently has an interest. Clint looked surprised to realize his southern-isms were working against him in the finale. I think with that realization, he would have made a conscious effort to become more the image Trump preferred. It's a pretty easy superficial makeover. He had already proven that he has the education, experience, and leadership skills to succeed when placed in any environment or situation. That's just one more task to complete.
Brandy's weaknesses are much more difficult to overcome. All season long we saw her deferring to others with "I don't know" or "it's your call" types of responses to requests for help with decisions. I don't think she was just playing below the radar, I think she was truly lost and incapable of competing on a meaningful level. She just lucked out to be on the winning team most of the time, particularly when she was put on Clint and Steuart's team. She can't acquire Clint's 10-15 years of actual business experience and knowledge in a superficial makeover. It's going to take her at least 10-15 years of hard work.
I wonder if Brandy really will be placed somewhere working with Ivanka or the other mini-Trumps. I hope so. Ivanka will be onto her weaknesses in a heartbeat. She seems like a very intelligent, no BS type of woman. Don Jr. and Eric will probably by blinded like their father by her beauty for longer, but will figure it out when she's unable to actually help them in a significant way. We saw Brandy truly shine only once, during the Rockport fashion show, as a presenter. She should have gotten the job that Stephanie got as the face representing Trump's organization.
No, Trump wasn't looking for a qualified apprentice for himself. He was looking for eye-candy. And he got it. Congratulations, you dirty old man.