Are you sure it's a phone screening case? There should not be a case (unless they've explicity said in writing that there will be). If there is indeed a case, it will be a simplified one - however, all of the same elements of casing are tested here (judgement & insights, structured thinking, clear communication, etc.)
However, this should be much more behavioral (again, depends on the wording of the email). The recruiter is looking to see if you're professional, likeable, etc. and if you're genuinely interested in (and have the capabilities for) the role.
- You need to be really clear on "Why consulting" as well as "why the company". You should also be ready with a resume walkthrough. More than that, you should be ready with questions of your own and be ready to talk through really any experience on your resume. Finally, be ready to play "tag"! I.e. try and get the recruiter to put you in touch with someone else at the company (reach out for more information on this
- Generally FIT answers are shorter and less in depth. "Why consulting" would be 1 min in an interview and 20 seconds on a screening call. Additionally, you need to have personal stories prepared for the FIT interview but not for screening.
- Be prepared to talk about your current job and any past work experiences