Recommended strategy for preparing for interviews

Bump.

Start with the guides/Rosenbaum. Understand the material, this is key. Don't focus on memorizing the answer, but focus on getting the logic behind the Why. This way you can also answer more challenging questions that may not be in the guide. Get through multiple guides cuz they have some different questions so good to cover many bases. Then, I would just focus on speaking with the current bankers. You should be able to quickly pick up on the lingo and then incorporate them into your answers to show you have a good understanding. The modeling courses, while helpful, might be a little extra. No one expects you to know how to model in as much depth as those courses go into. 

I think in addition to all that was already said; it's important to get a basic understanding for deal timelines, how firms make money, fundamental things like this can surprisingly go overlooked 

Of course every bank is a little different and my point may better be applied to a BB firm than a smaller boutique that focuses on solely M&A advisory. But to understand the difference in deal sourcing is a good thing to think about. Larger banks with lending arms likely already have relationships with clients though less profitable areas of business and hope to secure their M&A business over time (works similarly for dcm, s&t) which is pretty different from deal sourcing at a smaller shop that puts a lot more pressure on senior people to secure relationships without the client already being onboarded for a different business line. Just something to think about. Technical knowledge is great and important, but conversations are more important in my opinion. Anyone can learn to discount a series of cash flows, not anyone can be a normal receptive person in less formal conversations. Best of luck!