Hi marcmueller,
how you can say "I got 2 content types and also content for both content types" ?
When you add a content from the form of a content type, this content is linked with this content type, and that's all.
Then when you display the content view of a content, it use the content view of the content type with which it is linked.
So, like I said previously, if you need to have differents render for the content view, you must use override position or variations.
At the beginning of your override or variation, you can check the Itemid to chosse the layout to display
Best regards.
Lionel