If your ancestor naturalized, do you know how he had to live in the new country in order to naturalize? Do you know who could legally “vouch” for him if that was necessary? If you are using probate records, do you understand the general process of probate? What were the time requirements involved? Did they change over time? When your ancestor interacts with the legal system in any way, it’s advised to understand how that legal process worked. Not understanding the process can increase the chance that incorrect interpretations are made.
Your ancestor did not naturalize the minute he walked off the boat. Your ancestor’s probate did not begin two years after his death.