Sherod Moses Callaham or Sherod and Moses?

As one can see from the title, I want to hash out this person or people.  It is very commonly see in many genealogies that Sherod was Sherod Moses Callaham.  I have been looking at many trees and records that are available to see what I can determine about this man or men.

First we want to tackle what we know about Sherod.  He is the son of Nicholas Callaham and Mary Green.  He married Mary Ussery, daughter of John Ussery on October 3, 1786 in Lunenburg County, Virginia.  We know that she is the daughter of John because he is stated as surety of the marriage record.  This is really all I have been able to find on Sherod at this time. 

Now lets look at Mary, his wife.  On March 7, 1798, a Molly Calliham married a Mathew Calliham in Lunenburg County, Virginia.  John Ussery again served as surety.  On November 24, 1803, Mary is named in her father's will as Mary Calliham.  Mathew Calliham serves as a witness to this will.  It is believed that Molly and Mary are the same person, since Molly is a nickname for Mary and since she is a daughter of John and they both appear in the will of John Ussery in some form or fashion.

Now, lets look at what we have for Moses Callaham.  On January 1, 1800, a Moses Callaham married a Polly Ussery in Lunenburg County, Virginia.  This Polly is said to be "wife of Moses, daughter of John Ussery" in a land transaction.  On December 12,1805 sale of John Ussery's property, both Moses and Mathew buy land from John. 

I feel that Sherod and Moses must be two different people, and here is why:

1.  If Mary remarried to Mathew in 1798, then Sherod would most likely have died sometime prior.  Though I am sure it did happen, it was very uncommon for a women to leave her living husband and marry her brother-in-law in this time.  Mathew is also still alive in 1805, so Mary would still be married to him... unless she left him and went back to his brother?

2.  In 1810 census, Moses is listed as being between 26-44 years of age.  If Moses and Sherrod were the same, Sherrod would be listed as 45+ since he would have been well over 50 at the time.

3.  Polly is not necessarily the daughter of the same John Ussery.  John had a son named John, and depending on how old he was, he could have had a daughter who married Moses by 1800.   This could also explain why both men (Mathew and Moses) bought land from John Ussery's estate.

4.  If this Polly was the same one as Molly and Mary, then why did her father not serve as surety and why was she listed by her maiden name instead of her married name as she was in her previous marriage record?

I feel the confusion of Sherod and Moses comes from the fact they both married women who were named Mary Ussery (Molly and Polly are both nicknames for Mary) and both Marys were daughters of a John Ussery.  It would seem from the information gathered that Sherod and Moses were more likely two different people.  I have no idea who Moses's parents would be, except perhaps he was a cousin or brother of Sherod.  Moses would have been born after 1765 for the 1810 census to be accurate. 

Moses Callaham and Polly Ussery had the following children:  Martha, Elizabeth, Dolly, Patsey, Henry, James, John and Colin.  I have no children recorded for Sherrod and Mary Ussery, or for Mathew and Mary. 

Sources not mentioned in the above article:
Nicholas Callaham and his known descendants by Willie Mae Woods, 2000