Don't download other trees for the English Gross/ le Gros family until you have checked the historical records please.
Go back to William Gross of Normandy, a knight in the service of Sir Hugh de Montfort, who fought at the battle of Hastings 1066. Just click on my name and find my Gross family tree in my profile. Follow only my tree down til you get to the two men named Sir Oliver Gross (le Gros) who were father and son. One born in 1365 was the son of Lord John Gross of Sloley and Eleanor Felbrigg. He married Elizabeth Tuddenham, daughter of Sir Robert Tuddenham and de Clere.He fought with John of Gaunt. His son Sir Oliver Gross born about 1380 is the one who fought at the Battle of Agincourt in 1415. He married first Joan Brewse then Joan White, who was the mother of his children. He died in 1439. We have his Will and his tomb in Norfolk, which carries the arms of the families, Gross, Fellbrigg,De Clere, Tuddenham, Brewse and White.
Where your current trees go wrong is the assumption that Oliver was related to a Hugo le Gros married to Alecia. On the basis of the documents, his Will and his tomb this is not correct. He didn't have a family in France headed by Jean le Gros. So ignore this information. We don't match the French family on DNA. We think two le Gros family pedigrees got mixed up.
Instead follow Oliver's son John the Older Gross married to Heveningham.
This will lead down two lines- Thomas Gross the mariner from Great Yarmouth, Norfolk is the ancestor of the great shipping family called Gross. Thomas' nephew John Gross is the ancestor of a family of wool merchants from Kelsale, Suffolk, married to Margerey Chandler (Candle), a merchant family from Norfolk.
The descendants of John and Margery moved in waves to America, some via Cornwall, some via London. They include Isaac and William Gross. From the time they arrived in America I think the tree researched by TGross is correct.
Hope this helps.