Are overview questions off topic as not a good fit for StackOverflow / StackExchange?
"Are overview questions a good fit for Christianity.SE?"
The answer to that is, "it depends." While there may be cases where the OP is looking for the viewpoint of multiple groups / denominations regarding a specific question, the key is that the question should be a focused question.
While overview questions may exist, that doesn't mean that they are good questions. All questions still need to be good questions, showing some level of research and understanding of the topic. Blanket overview questions which are those fishing for answers are not a good fit for Christianity.SE.
For a "deeper dive" please continue reading Caleb's detailed meta answer.