I'm fairly new to salesforce. So please bear with me if this question turns out to be quite basic.
I've been doing the migration project from salesforce to Dynamics CRM online and one of the modules to be migrated is Case.
In salesforce, the case module seems to be heavily customized with 20 something profiles, record types and page layouts. So the page layout matrix is quite huge and complex (at least for me). So far I've figured out that each profile can be assigned record types (one of these can be set as default) and the page layout assigned to that record type will be shown to the user. But it looks like users can see other page layouts outside the record types assigned.
To give an example, I have profile, 'Profile A', with only one record type 'Record Type A' assigned to this profile. The page layout assigned is 'Case Layout A'. But this page layout is only shown during creation of the case. Once the case is saved and the user clicked Edit, it's showing another layout, 'Saved Case Layout B', whose record type is not added to the 'Profile A' at all.
How exactly is this page layout definition evaluated? Am I missing some other rule setting? I've scoured through salesforce documentation and the only articles I can find are for simple scenarios or how to create basic assignment scenario.
Thanks in advance!