The Jehovah's Witness (JW) Leaders teach that:

This means that the first reference works that the Theocratic minister will consult will be Theocratic ones, the Watchtower publications.
(Theocratic Aid to Kingdom Publishers 1945, 220, 223)

Besides declaring their own publications "the best" the JW Leaders have also, since the 1870s, heaped thousands of criticisms upon "apostate Christendom" for its alleged "false teachings".

It is strange, therefore, that JW leaders often use "apostate" works to support, or give credibility to, their own doctrines! It is even stranger that "apostates of Christendom" often had correct understanding long before the "best Bible helps", those of the Watchtower Society, were available and got things wrong!

For example, when the Governing Body changed the interpretation of "this generation" (w1995 11/1) they cited four scholars for support – Bauer, Vine, Thayer and Kittle.

Greek-English Lexicon of the New Testament, Walter Bauer (1877-1960).

Bauer was a German lexicographer. Taught at Gottingen 1916 to l945.

Vine’s Expository Dictionary of New Testament Words, W E Vine.

William E Vine (1873-1949) opposed Jehovah’s Witnesses and called their doctrine of conditional salvation and the denial of the Trinity "heresies". Yet Insight On The Scriptures Volumes 1 & 2 (1988) refer to Vine for support some 52 times!

Vine was a Greek scholar, educator, editor, pastor and author, educated at University College of Wales. He obtained a BA and MA in "Ancient Classics" from University of London and was pastor at Manvers Hall Church in Bath for 40 years. He celebrated Christmas, believed in Hell and believed that Christ is God and that all believers should partake of the Lord’s Supper – beliefs that JWs reject.

Thayer’s Greek-English Lexicon of the New Testament (1889).

Joseph Henry Thayer (1828-1901) was an American New Testament lexicographer, ordained pastor in the Congregational Church, professor of sacred literature in Andover Theological Seminary (1864-1882 and lecturer at Harvard Divinity School (1883-1901).

The Theological Dictionary of the New Testament (1964). Edited by Gerhard Kittle.

Gerhard Kittle (1888-1948) was a German Biblical scholar and university professor of New Testament.

Furthermore Insight On The Scriptures Volume 1, p. 440, cites Strong and Robinson for support:

Strong’s Exhaustive Concordance of the Bible (1890).

James Strong (1822-1894) was a Methodist biblical scholar, educator and a member of the Anglo-American Bible Revision Committee.

B Edward Robinson’s Greek and English Lexicon.

B E Robinson (1794-1863) was an American biblical scholar.

The above authorities are all dead, were college educated in theology including Greek and Hebrew by "apostate Christendom", and knew nothing of numerous later doctrines JWs called "Bible truth" in books that were supposedly "the best available" compiled with direction of "Jehovah's spirit".

Yet, these men who were schooled by "apostate Christendom" in the "wisdom of this world" are authorities for "new light"!