You might find something in https://landedfamilies.blogspot.com/2015/11/195-arundell-of-wardour-castle-and_18.html as a guide. "Arundell, John (c.1392-1423). Eldest son of Sir John Arundell (1367-1435) and his wife Eleanor, daughter and heiress of Sir William Lamborne of Lamborne, born about 1392."
Arundell, Sir John (1367-1435), KB. "He married 1st, 2 May 1386 (div. 1388) at Mursley (Bucks), Margaret, daughter of Sir Robert Tresilian, and 2nd, c.1388, Annora, daughter and heiress of his stepfather, Sir William Lamborne of Lamborne (Cornwall), and had issue:
(2.1) John Arundell (c.1392-1423) (q.v.);
(2.2) Sir Thomas Arundell (d. 1443), kt., of Lanhadron; MP for Cornwall, 1417, 1419, 1429 and 1435; High Sheriff of Cornwall, 1422-23, 1426-27, 1432-33 and of Devon, 1437-38; JP for Cornwall, 1433, 1436-43; married 1st, Margery (d. 1420), daughter of Sir Warine Arcedeckne but had no issue; married 2nd, c.1426 (settlement 17 December), Elizabeth (d. 1477) (who m3, Robert Burton), daughter of Sir Thomas Paulet of Hinton St. John (Wilts) and widow of William Bykbury, and had issue two sons (from one of whom descended the Arundells of Tolverne and later Truthall) and two daughters; died 24 June 1443;
(2.3) Sir Renfrey Arundell; married c.1421 (settlement 9 September), Joan (d. 1497) (who m2 John Nanfan and m3 Sir William Houghton), sister and heiress of Sir John Colshull and had issue two sons;
(2.4) A daughter;
(2.5) A daughter."
The author seems to have based this on the following sources:
Sources
L.G. Pine, New extinct peerage, 1972, pp. 8-12; E.D. Webb (ed), Notes by the 12th Lord Arundell of Wardour on the family history, 1916; B. Williamson, The Arundells of Wardour, 2011, passim; R. White, Cottages ornés, 2017, pp. 74-76; Oxford Dictionary of National Biography entries on the Arundell family of Lanherne, and the 1st and 3rd Barons and Lady Blanche Arundell.
Location of archives
Arundell family of Lanherne: deeds, manorial records, family and estate papers relating chiefly to Cornish and Dorset estates, 12th-19th cents. [Cornwall Record Office, AR; 1005; X609; AD1896; AD1906]; estate survey, 1659 and misc family papers, 15th-17th cents. [Royal Institution of Cornwall]; letters to Richard Bellings-Arundell, 1709-19 [Wellcome Library, London, MS 8463]
Arundell family of Wardour Castle, Barons Arundell of Wardour: deeds, manorial records, family and estate papers relating chiefly to Wiltshire, Dorset and Somerset estates, 14th-20th cent. [Wiltshire & Swindon History Centre, 2667; 750; 413/507]; deeds, manorial records and estate papers relating chiefly to Chideock estate, 13th-18th cents. [Dorset History Centre, D16]; papers relating to family trust, 18th-19th cents. [Warwickshire Record Office CR1998]
