Most private defense lawyers offer free consultations. Schedule a few and ask what they can do to help. It's not possible to give a definitive yes or no answer to your question. There are too many variables in a criminal case. That's where a consultation can help.
Robert Guest is a Kaufman County Criminal Defense Lawyer with offices is Forney, Texas and Rockwall, Texas. My use of Avvo is not intended to form an attorney-client relationship. Avvo is a limited forum and should never be used as a replacement for a consultation with a local lawyer. My answers are not legal advice. You really need a consultation with a local attorney.
There's no guarantee that a retained lawyer will be better than a court-appointed one; some court-appointed lawyers are actually very good at what they do.
To add to Mr. Guest's answer, please be aware that many lawyers will not talk to a person who's already represented by an attorney, so before you do this your brother may have to make a request to the judge for his current attorney to withdraw from the case so that he can hire an attorney.
Who is the best lawyer to defend a case?
Retained? Appointed? No real way to say for every case. Some lawyers are good for some cases but not others, without even going into whether they are appointed or retained.
First couple of steps in the situation you outline would seem to be (1) your brother have a businesslike conversation with his current lawyer about how the case is being handled; (2) your brother get a second opinion from another lawyer.
Most courts I deal with do not favor a delay for change of counsel at the last minute, so the sooner your brother's concerns are addressed, the better.
Answers on Avvo are for general information purposes only and should not be relied upon as legal advice. No attorney / client relationship is created by providing this answer. For specific advice about your situation, you should consult a competent attorney of your choosing.