I am having trouble explaining a short list of ships from Jan Glete's notes

I have been fascinated by a short list of ship names from Jan Glete's notes from the Nationaal Archief when he was doing research a long time ago for his book Navies and Nations (I believe). The list has some very interesting names, and was included in his notes about Directors' ships hired in 1652 and 1653. This is the list, dating from 30 March 1652, as best as I can recreate it:

Colburg
Harderin
Harderwijk
Herenberg
Wesp (Weesp?)
Zutphen

The list is a problem, because we think that we know the composition of the "Fifty Ships", none of these names are part of that list. Rick van Velden was not able to find the list from 30 March 1652, so finding the truth will entail searching in the Nationaal Archief, presumably under the area where the Directors' ships information is located.