There is way to fix this with an ADD-ON. Go to the ADD-ONs, Click Get Add-Ons,
Key in SPLIT NAMES. Click FREE to install the add-on.
Highlight your column with the names to split. Run the Add-On by clicking start.
I highlighted the names in Column A and clicked ONLY first name and last name. Then clicked SPLIT.
FINISHED SPLIT. I would probably delete Column A after split has been completed.