You actually touch on a very important point here. Many candidates don't understand what distinguishes the clarifying questions at the start from later analysis-related questions (asking for market data, financials, etc.).
In general, asking such analysis-related questions at the start is bad! It comes across completely arbitrary, and the interviewer will ask himself why you are asking analysis-questions before even having layed out an analysis approach (the structure)! It just makes no sense to ask for data before laying out your structure, because this information will have ZERO impact on this structure (--> the logic according to which you should address the question).
The clarifying questions you ask at the beginning have the following objectives:
- Completely understanding the context/situation (including, unclear terminology, but also, for example, the business model of the client (e.g., "How do they make money?") if unclear!)
- Understanding/narrowing down the actual question(s) of the client (very often the question is poorly/vaguely stated in the prompt, and it is your duty as the candidate to make it precise!)
- Understanding (and quantifying if applicable) the underlying objective(s) of the client
These questions are aiming at understanding the initial setting, hence forming a precondition to outline your structure towards answering the core question (the issue tree)!
The later analysis-related questions that you ask while navigating through the case are then aiming to verify the actual relevance of each sub-branch in your tree. So if you have defined and disaggregated the criterion to answer the client's core question in a clean way, all these leater questions follow a this precise "roadmap" as layed out by your tree. These questions then oftentimes also comprise enquiries on current performance metrics (revenues, costs, growth rates etc.), which normally never make sense to be asked in the clarifying questions (before making explicit your structure).