At the hearing level a lawyer is more important than ever, although all the forms and applications completed in the earlier two stages could come back to hurt you in a hearing (if you did not get legal help in completing those forms on your initial and reconsidered application.
Once you know your case is going to a hearing your disability attorney will do a deep review of the evidence ant then tell you what is lacking in your case (to be able to prove disability) and what you can do to make your claim stronger so that it will be approved.
Once your hearing has been scheduled, your lawyer can tell you what the particular Administrative Law Judge (ALJ) might ask you in a hearing and what other aspects of the hearing the claimant should get ready for. Being adequately prepared for the hearing will make you do better answering the ALJ's questions.
If you are unprepared in a hearing you could really harm your chances of winning.