I note 7 of children you mention, 6 in Liverpool and Hannah in Ulverstone, note below there were 2 others in Ulverstone.
WILSON, HANNAH mmn LISHMAN
GRO Reference: 1854 M Quarter in ULVERSTONE UNION Volume 08E Page 561
WILSON, WALTER 1855 ULVERSTONE UNION
WILSON, GORDON 1856 ULVERSTONE UNION
I was hoping that the names of any females might give a clue to the wife of Thomas but of 12 records 1817 – 1821 there are none. Do you know where and when Hannah was born?
As for James 1817 Sorbie, distance may not be the answer, if it is there are two closer.
Sorbie, Wigtownshire is 59 miles W of St Cuthbert, Cumberland .
JAMES WILSON 29/09/1819 Dumfries THOMAS WILSON & MARY FORRESTER
Dumfries, Dumfriesshire is 28 miles NW of St Cuthbert, Cumberland
JAMES WILSON 17/04/1819 Penpont THOMAS WILSON & AGNES THOMSON
Penpont, Dumfriesshire is 47 miles NW of St Cuthbert, Cumberland.
But the other 9 should not be discounted.
Colin