If you have it from me or my research, say so. I have shared my research with you for several years and you should be careful to let others know how you came to have the informatin you have that allows you to formulate your next question.
That is all that is required as you move forward with the research. This is not self-aggradizment--I just want to know where you have been in your reseach and where you expect to go. Your readers, hopefully, want the same.
Duplication of effort is not ever useful. None of us have that much time.
Youy cannot be hurt by readily acknowledging those who came before. That research will never subsume your new documentation and presentation.
Take what is given to new understandings, but do not fail to let your readers understand how, and by whom, just how you understand your research to demonstrate the ancestry.
PS--Describing me as an inhabitant is exactly the problem betwween us just now. I live these families, pulse them.
I descend from them. I don't inhabit them. I inhabit my apartment.
I don't 'frequent' my ancestors, rather I am their product and acknowledge their combination. I can see who their combinations turned out. What I want to see is how they came together and how their parents came together.