Is it possible to know which join rule were used when migrating from MIIS to FIM ?

We are under migration from MIIS to FIM.

We disable Provisioning and Full import of GAL MA of FIM.

Most of connectors were successfully joined by existing MIIS join rule.

 we CSexport-ed MIIS and FIM connector data using below script that change XML to CSV data

http://jorgequestforknowledge.wordpress.com/2013/02/08/parsing-a-csexport-generated-xml-file-into-a-scoped-csv-file/

and compared disconnectors of MIIS and FIM.

But we found in some GALMA, there are around 1000 not-joined object  by current join rule.

I would like to know how to solve this problem.

Is there any good idea ?

or,  how could I know which join rule were used when joining and why those 1000 not-joined object are not joined ?