If you're using dynamic addresses and the node goes down, the IP address moves.  SMB, however, will be confused, because you've lost the state.  If you're only reading, you're probably OK - the client sees this and will reopen the file.  If you have files open for write, you'll annoy it and will lose your writes - your client will figure out that your server has gone away and will no longer be able to save your file.  If you do this with something like an Access database or Outlook PST open on your share, you'll be very unhappy.  At best, you'll need to restart Outlook.  Worst case, you'll corrupt the PST.  This is the same thing as would happen if you had a traditional Microsoft cluster with a floating IP between 2 nodes.  When you fail over, you'll see a brownout.
What happens if we keep using dynamic IP pool for SMB shares?
Why it is recommeneded to use static IPs for SMB shares?