Here is the list based on Randall Collins - only philosophers BOLDED by him in his diagrams are listed here. I excluded the Greco / Roman period as that list has already been studied based on the Leob Classic Library catalogue - so effectively it started from Chapter 9 onwards. I group things based on period after seeing the list.
A) High Medieval
Henry of Ghent
William of Ockham
Levi Ben Gerson
B) Early Modern
C) Modern / German Eminence
(20th century - not to be included in list)
I am somewhat surprised of his list for 19th c. Based on my analysis on what is being taught in American University, I have a sense that the 5 "canonical" continental philosophers of the 19th century are Fichte, Hegel (he has included), Kirkegaard, Marx and Nietzsche. Of course, arguably, this list was based on the professors who taught in late 20th century who grew up studying Existentialism and Heideggar, thus the focus on Kirkegaard and Nietzsche.