>>56654879/resource/fldmmdl of bwmirror has a pretty interesting document. I found it hoping it would have an index of some sort for the corresponding graphics since it list most trainers.
revision 2642 (Feb 2009) is how it started with the usual DP placeholders.
revision 12868 (Nov 2009) for example list gym leaders 1 and 5 as female and doesn't list type specialty. It also looks like Hilbert started development with a White Hat.
Sadly it lagged behind and it doesn't keep up with the rest of the repo. It also has a list of pokemon but it never seems to go past Arceus.
Here are those 2 revisions. fldmmdl_list.xls
https://litter.catbox.moe/yso81l.7z 