There were certainly several Caldwell families farming in Magherangeeragh in the tithes. No Wallaces though in the parish.
http://www.irishgenealogyhub.com/tyrone/tithe-applotment-books/parish-of-termonamongan.php
Still several Caldwell familiesthere in 1901:
http://www.census.nationalarchives.ie/pages/1901/Tyrone/Maghernageeragh/Magheranageeragh/
And 1911:
http://www.census.nationalarchives.ie/pages/1911/Tyrone/Magheranageenagh/Maghernageeragh/
Letters of Administration (with the Will annexed) of the personal estate of Henry Caldwell late of Maghernageeragh County Tyrone Farmer deceased who died 11 June 1865 at same place were granted at Londonderry to William Hamilton Caldwell of Ballylawn County Donegal Gentleman the Son and a Legatee.
Above will is on-line on the PRONI website. Mentions wife Frances and his children.
Letters of Administration of the personal estate of William John Cardwell late of Magherageeragh County Tyrone Farmer who died 5 February 1894 at same place were granted at Londonderry to Eliza Caldwell of Magherageeragh the Widow.
Above probate file destroyed in the 1922 fire. No papers survive.
Following probate files should all be in PRONI (personal visit required to view them).
Probate of the Will of Eliza Caldwell late of Maghernageeragh County Tyrone Widow who died 14 April 1911 granted at Londonderry to Samuel Caldwell Farmer.
Probate of the Will (with one Codicil) of Charles Caldwell late of Maghernageeragh County Tyrone J.P. who died 17 February 1914 granted at Londonderry to William Caldwell Farmer
Probate of the Will of the late Mary Caldwell, Magherngeeragh, Co. Tyrone, Widow, who died 12 March 1918, granted at Londonderry 13 June 1919 to William Caldwell, Farmer. Effects: £367 15s.
Caldwell John James of Maghernageeragh county Tyrone farmer died 11 December 1927 Administration Londonderry 16 April to Rebecca Caldwell the widow. Effects £143
Caldwell William of Maghernageeragh Castlederg county Tyrone retired farmer died 31 January 1948 Probate Londonderry 18 June to James Hemphill and William Henry McCormick farmers. Effects £3599.
Caldwell Robert of Maghernageeragh Castlederg county Tyrone farmer died 11 November 1948 Probate Londonderry 23 June to David A. Hamilton justice of the peace and Gerald Ferdinand Victor Leary medical doctor. Effects £1378 9s. 2d.
Caldwell Rebecca Jane of Maghernageeragh Mournebeg Strabane county Tyrone widow died 30 January 1951 Administration Londonderry 10 April to Annie Elizabeth Hamilton married woman. Effects £312 4s. 8d.
The Caldwells look to have lived in the townland since the 1600s. By way of example, here’s a lease in PRONI dated 21.10.1678 (D2281/1).
"Edward Edwards of Castlederg, Co. Tyrone, to William Caldwell of Maghernageeragh, Co. Tyrone. A lease of 3 lives renewable for ever at the yearly rent of £5 10. 0. with 1½ barrels of good oats and one fat unshorn mutton and 3 days work of man and horse. Maghernageeragh and Thainboy, [sic] Co. Tyrone". It's probably worth checking that lease to see who the 3 lives were. You may get a snapshot of who was in the family at that early date.
D2281/3 is a will for Charles Caldwell of Maghernageeragh dated 10 Oct 1747.
PRONI have about 15 items for the family. Search their e-catalogue under Maghernageeragh & Caldwell.
