Soules Faction

[Aulyin]

Many of us know that the Soules/Sules family held Liddesdale in Scotland from the 12th century until the 14th but I have a theory about the Solway/Sulewath being named after the Soules/Sule or vice versa.
Are these "coincidences:
The most eastern river entering the Sulewath on this map:
http://maps.nls.uk/scotland/view/?sid=00000364 is named Solueus fl. and on map: http://maps.nls.uk/scotland/view/?sid=00000217 and http://maps.nls.uk/scotland/view/?sid=00000258 The most north easterly river entering the Sulewath on this map: http://maps.nls.uk/scotland/view/?sid=00000587 flows from Hermitage Castle (held by Soules). Between Dumfries and Caerlaverock Castle on the river Nith sits "Solway". As it does on the map at: http://maps.nls.uk/scotland/view/?sid=00000201 and http://maps.nls.uk/scotland/view/?sid=00000197 and http://maps.nls.uk/scotland/view/?sid=00000200
No information on this.

William Soules, Butler of Scotland, was interned for treason against Robert Bruce in 1320 and his lands were forfeit, many of them by the Douglas family.

[Aulyin]

William Lord Soulis possessed:
"The whole district of Liddesdale with Westerkirk and Kirkandrews in Dumfriesshire, the lands of Gilmertoun near Edinburgh, and the rich baronies of Nisbet, Longnewton, Caverton, Maxtoun, and Mertoun, in Roxburgh."
Saltoun was originally named Soulistoun.

He was the Governor of Berwick and had been King Edward Bruce's Governor of Dundalk.

Berwick Castle
Lord Soulis Tower (also called Lord's Mount) which was begun in Edward's reign and finished in that of Mary, 1555. This is the northeast angle of the Edwardian walls. Lord Soulis was a supporter of Bruce, and was appointed Governor of Berwick. He rebelled against the king, was captured and imprisoned. This was the time when Berwick was controlled by Scotland.
http://freepages.genealogy.rootsweb.ancestry.com/~agene/berwalls.htm

See The Scottish Nation - Soulishttp://www.electricscotland.com/history/nation/soulis.htm

[Aulyin]

In all previous mentions of Edward Bruce in Ireland it is Sir John Soulis who is mentioned but in An Illustrated History of Ireland by Margaret Anne Cusack I came across Lord Walter:

Edward Bruce, who had, with his adherents (the Lord Philip Moubray, the Lord Walter Soulis, the Lord Allan Stuart, with three brothers, Sir Walter Lacy, Sir Robert and Aumar Lacy, John Kermerelyn, Walter White, and about 3,000 others, writes Pembridge), encamped, not two miles from Dundalk
http://www.libraryireland.com/HistoryIreland/Edward-Bruce-Invasion.php

Strange that there are three "Walter"s mentioned in this paragraph? I take it that this is an error.