Maj. John Nichols - Help to verify this line please?

https://media.geni.com/p14/7c/de/6d/e2/534448685d5128a5/maj_john_nichols_original.jpg?hash=618bd9c49b306002c5cc692d6d6faac50f057338e733041156913cfa44bf5b14.1741935599

He showed as direct to me--- 10th great grandfather before I disambiguated John Allen from John Taylor Allen.
The Allen in question is husband of Sarah McDowell.

See https://www.geni.com/discussions/285811

Sarah Allen
my DNA proved 6th great grandmother and her husband my grandfather that I have NOT DNA confirmed as of yet
John Allen who is disputed as being a different man from
John Taylor Allen, Sr/John II
but many think 'MY" Allen was the son of DAR patriot John Allen, Sr.

But not likely because locations don't line up for Sarah Allen to be the same person as Sarah Ann Allen
meaning John Allen and John Allen, Jr. and John Taylor Allen, Sr/John II are three different men.
Agnes is conflated elsewhere as well---
Agnes Allen
Agness Allen

Others are still working on the DAR line and I hope to add their research here soon.

Tagging individuals who may be able to help if have time please:
Annber Lynn Collins
Faustine Darsey on partial hiatus
Dan Cornett
Private User
Erica Howton
Vicky Hilton