It's still too early to assume. But I am noticing some intersting coincidences. I'll start with direct connections to our Alexander.

Kerr -
The Kerr connection that Rob found with an Alexander Sinclair conducting tobacco business in Jamestown with a Kerr. This is a very solid connection between the families. We know these Bogles were of the Stevenson line.

There were marriages between the Kerr family and the Sinclairs of Stevenson.
Sir Robert Sinclair married in 1732, Isabella, only daughter of Colonel James Kerr by whom he had many children, one of which took the Lockhart name.

James Sinclair, Lord Rosslyn about 1670, has a daughter, Helen, born March 15, 1670 married Henry Kerr of Gredane in the Mers.

Alexander Kerr, Jacobite crossed Jan 14, 1716 on the Elizabeth and Anne from LIverpool to York, Va. Alexander and his brother Henry were sons of Archibald Ker(r) of Graden and Helenor St. Clair, daughter of Sir James St. Clair of Roslin. The boys' father died when they were still young children. Their mother raised them as Roman Catholics. Henry, the eldest, may or may not have participated in the 1715 Jacobite Rebellion. However, Henry was not captured as a Jacobite until the 1745 Jacobite Rebellion near Forfar, Scotland.

Bogle -

We know there was a lawsuit Rob found wherein the Bogles of Jamaica sue the estate of our Alexander. This is a direct connection to our Alexander.

We know that there was a Bogle & Scot company shipping Virginia tobacco from the Rappahannock and York rivers to Great Brittain, probably thru Whitehaven then overland to Glasgow.

Two crossings of Bogles to Virginia -
Bogle, Matthew, s. of Robert Bogle, tobacco merchant,
res. Glasgow, sett. Va. 1729, to Glasgow 1736.

Bogle, William, merchant, sh. 9 Oct. 1685 fr.
Port Glasgow to Va. , on Mayflower of Preston

The Bogles of the Easter Sugar works.
BOGLE George - Easter Sugar Works Glasgow 1669 Hutcheson
BOGLE Robert - Easter Sugar Works Glasgow 1736 Hutcheson

The Patterson connection to the Easter Sugar Works.
PATERSON, James - - Easter Sugar House, Glasgow 1799> Hutcheson

We know that three of Robert Sinkler's children married sibbling Patterson (Patteson's. as some spelled it). Robert Jr. married Lucinda aka Lucy, John married Elizabeth aka Betsy, and Nancy married John Delafayette Patterson. The point is their ancestry. They were children of Edward Taylor Patterson, who was the son of William, son of Thomas, who was born in Scotland in 1657, and immigrated to Virginia, where he died in 1765. Thomas may have come about the same time as Alexander, since they were close to the same age.

Thus, we can tie our Alexander to the Easter Sugar House, owned by Bogle & Scott, who clearly had strong connections via marriage to the Sinclairs of Stevenson.

We know the Sinclairs of Virginia were doing business with and/or for the Bogles.
From the Bogle papers we have -
"One reference which appeared was in a letter from George Bogle jnr to his father, London, 19 August 1727: ..........."Mr Carstaires writes me he has no receipt for the arrack? but that it was delivered to one James Hail/Hall sailing with Robert Sinclair. As to the tea".......Arrack is a liquor made from sugar cane.

In December 1731 George Bogle married Ann Sinclair (daughter of Sir John Sinclair of Stevenson). She had a brother William, who was a broker and merchant in London. By the late 1730's he was based in Kingston Jamaica and the main emphasis of the Bogle operations seems to have moved away from tobacco towards sugar. He was working closely with George Bogle.

Sir John Sinclair of Stevenson's second son, John assumed the surname Lockhard and married Charlotte, d. of Jas. Bogle, W.S. about 1715.

Scott -

We know Alex was indentured to John Scot of Virginia. The 4 yr. indenture period is a clue as it is an odd number, the norm being 5 yrs, so we suspect Alex may be family... perhaps marrying into the Scott family (only a theory).

We know that there was a Bogle & Scot company shipping Virginia tobacco to Great Brittain, probably thru Whitehaven then overland to Glasgow.

There are Scot marriages amonng the Stevenson line. But the name Scot in Scotland is like Smith in America. There were thousands of them.