I have noticed the double Tatton entry in TTFBM for years and chalked it up to an LL editing miss. FBTW did take place 20 years before SL as Tatton fights in the battles of Arques and Ivry which occurred in 1589 and 1590 respectfully. He then returned to England, wrote about the battles, sailed to America and returned to Ireland with a wife and treasure around 1592 based on his travel to and time spent in London and adventures in America. Barnabas most likely found the first purse of coins around 1598 in the beginning of SL. I think LL wanted Barnabas and Tatton to link up, but the timing doesn't fit. I also like to think that the burnt hulk Barnabas takes shelter in on the Carolina coast is the remains of the original Spanish treasure ship Tatton takes the chests from in FBTW. What makes more sense for the future story would be for Brian to help Tatton in some way or for Noelle to meet one of Tatton's children. The timing could have worked for this to happen in subsequent Chantry or Sackett stories.