Hey Adrian and
@Chris Brown and first of all congratulations on reaching the final stage! As for your query, you will appreciate that for reasons of fairness and confidentiality I will not be able to list the specific questions I was asked. I can however give you some general thought on what I think is meant by the phrase mentioned in the email and on how you could go about preparing.
By "commercial motivational questions" I think the firm simply means
questions that test your (i) ability analyze commercial factors and (ii) to link them to your motivations. For instance, you may be asked about the firm's competitors - and say you then list some firms. However, you could then be further asked what were the specific criteria you chose to identify competitors by, and why did you consider those aspects of the firm to be more relevant than others. Then, you may be asked why would you prefer
Willkie over its competitors or over other firms you have been applying for. You could once again list a number of aspects in which
Willkie does better than the others. However, you could once more be asked why do those factors specifically matter more to you than other factors that would have favored those other firms.
To give an example, say you are comparing
Willkie with Milbank. If asked why you applied for Milbank, you could mention its finance expertise, whereas for
Willkie you could mention its PE practice. Now,
Willkie has a premium high-end PE offering, whereas Milbank, having recently acquired Dickson Minto, has one of the best mid-market ones. However, Milbank also has one of the best high-end finance practices, whereas
Willkie's is more mid-market. In explaining why you prefer
Willkie to Milbank, a great answer would not just elaborate on why you prefer to work in a team with a focus on high-end rather than mid-market PE deals; but it would also explain why working at the top of the market in PE is more attractive to you than working at the top of the market in finance. This is an example of a situation where your response will involve a lot of commercial analysis, but where you would eventually return to a question of your interests and experiences.
As for the question about guidance, I am afraid I cannot say a lot more than I did in a previous post. I would try to research in depth the type of work the firm specializes in, to have a real understanding of what its different practice areas do and how they come together in a transaction/case. I would also try to make my answers to the main motivational questions as persuasive as possible, ensuring the analysis is nuanced and can withstand further questioning. Finally, I think you could benefit from practicing formulating your thought process out loud and making best guesses. You might be asked questions where there is no expectation for you to have known the answer prior to the interview but where you could get close to it by working from what you know and with the help and guidance of the interviewers.
