They are experts on Islam. Some were MIssonaries to Muslims, who studied their languages, histories and cultures firsthand. Others are well established scholars of various races.
Your avoidance of those sources tells me a lot. Abraham Geiger is a Jewish Scholar, not an old white man.
In fact, his works have been noted by many scholars.
James Arlandson
https://www.americanthinker.com/author/james_arlandson_and_soliman_albuthe/
James M. Arlandson teaches World Religions, Humanities, Introduction to Philosophy, and Introduction to Ethics at various colleges. He has written many articles and one book, Women, Class, and Society in Early Christianity (Hendrickson, 1997). His Ph.D. is in Comparative Literature (ancient Greek literature, religious studies, and critical theory).
https://myislam.dk/articles/en/arlandson a00-islamic-sharia-law.php
Samuel M. Zwemer
https://nortonsafe.search.ask.com/w...4-10&ver=22.17.0.183&prt=Default&trackId=nsss
Charles Cutler Torrey
TORREY, CHARLES CUTLER° (1863–1956), U.S. Bible scholar and Semitist. Born in East Hardwick, Vermont, Torrey taught Latin at Bowdoin College (1885–86), and Semitics, Bible, and Hebraica at Andover Theological Seminary (1892–1900) and at Yale University (1900–34). He was one of the founders of the American School of Archaeology in Jerusalem. Subsequent archaeological finds and advances in Semitic linguistics and in lower and higher biblical criticism have been damaging to many of Torrey's contributions in the estimation of present-day scholarship.
https://www.jewishvirtuallibrary.org/torrey-charles-cutler-x00b0
Charles Cutler Torrey (20 December 1863 – 12 November 1956)[1] was an American historian, archeologist and scholar who presented manuscripturial evidence to support alternate views on Christian and Islamic religious sources and origins. He founded the American School of Archaeology at Jerusalem in 1901.
Torrey taught Semitic languages at the Andover Theological Seminary (1892–1900) and Yale University (1900–32).
Some of Charles Cutler Torrey's studies are included in The Origins of The Koran: Classic Essays on Islam’s Holy Book edited by Ibn Warraq.
https://nortonsafe.search.ask.com/web?chn=PIF001&cmpgn=&doi=2019-04-10&geo=&guid=084631e7-8e44-4d5e-935a-795ea1c3bef7&o=APN11908&p2=^EQ^cd0aus^defzzz&prt=Default&trackId=nsss&ver=22.17.0.183&tpr=2&enc=2&q=f4y0cUCsx88BagAmJxkShSugVU_CFWR1bAK27oyL8vbvADmLgF-nMXTSgkJqlSWXc2kPgWgLo6o2zfy1D8T4y86FEQLW2juJIf9DV1muTh4ZufP5PSkXrOJP3d5b7LeWS4rbIobjxLlZ_19S1Y9ht0sCYTU2lnjYDWJ1et5XJQ0DYSvdljAjeaUw_NOCnaTlCP2H0Qrn5Y4LvFw1XQkjNjXDh1rarzgWxJSLdYZxbIFASvCe8mlRHFPkSu36k-xJQTq1h4mwoPbVHGp2ZNDc4tEu7m_lZ2KgATy34lttNfH0d04T8oLs2z4EdzdVQjOgyynqwTRNot3AeQWPtJf9Xw&ts=1555966172544
William Montgomery Watt, Professor Emeritus of Arabic and Islamic Studies at the University of Edinburgh, is well known as an authority on the life of Muhammad and the origins of Islam. His many books include the Faith and Practice of Al-Ghazali and Religious Truth for our Time
These people are very qualified to speak on the subjects related to Islam and the Koran.