Merging clientCorporations with the API

[DrPineapples]

The context of this question is I'm trying to merge two clientCorporation entities with API calls. I've written a script to find all entities and fields of entities associated with the clientCorporation entity and update the id where possible. This has been successful as far as I can tell, except for Placement entities.

While they seem to transfer over in most places, under the Submissions tab, they don't. I've checked the endpoints the webapp calls, and the endpoints
"/search/Placement?fields=id&query=jobOrder.clientCorporation.id:##"
and
"/query/Placement?fields=id&where=jobOrder.clientCorporation.id=##"
give different results. Is this intentional?

I would appreciate any advice on what can be done to resolve this, and also if you have any other tips / things I might have missed when completing my merge.