Should I split my tests in several assemblies when testing different configurations?

With the perspective of writing a library assembly. I want tests that shows how the library works with other libraries. As an example, say I want to show how to use it with OrigoDB, MongoDB and Sql Server.

Would you split these scenarios only by test class, or would you further split them by assembly?

My reasoning is that if I split them by assembly, the OrigoDB tests assembly won't have dependencies it doesn't need, which could potentially make the requirements unclear.

On the other hand splitting it up like that causes there to be a lot of test assemblies which I don't know, but suspect would slow down my IDE and fragment the test-code. The latter problem could of course be overcome by using a solution folder for all of the test assemblies targetting a library assembly.

In short, I'm after a best practice and or personal opinion on what's good along with reasoning why you'd go with one over another.