[doctoboggan]

I just copy/pasted your exact logic puzzle into Claude-3.5-sonnet and it solved it right away. Here is the response:

    Let me help you solve this step by step.

    First, let's identify what we know about Samantha:
     Samantha has 2 brothers
     Samantha has 4 sisters

    We also know that:
     Alex is one of Samantha's brothers
     Alex and Samantha share all siblings

    Now, from Alex's perspective:
     Alex is one of Samantha's brothers, so he has 1 other brother (since Samantha has 2 brothers total)
     Alex has Samantha as a sister, plus her other 4 sisters
     So Alex has 5 sisters total (Samantha + her 4 sisters)
     And Alex has 1 brother (the other brother besides himself)
 
    Therefore, Alex has:
     1 brother
     5 sisters