The key here is to be genuine about the rationale behind your preferences while also catering your answer to the size of the team you are interviewing for.
If the PE firm you’re interviewing with is a megafund, then it would make sense to highlight the advantages of big teams more. These advantages include more infrastructure and resources to learn from, a wider network of groups to work with and collaborate with, and the opportunity to work on more sophisticated deals with greater access to financing, co-investors, and different capital structures.
Keep in mind, you can still mention that you also like working in small teams especially especially if the group you’re interviewing is a small team. The important thing is to also mention the benefits of being part of a larger firm and having a large network of colleagues and resources.
If the PE firm you’re interviewing with is a mid-market fund with a smaller team, it may benefit you to highlight some advantages of small teams. These advantages include: gaining more responsibility, learning a broader set of skills, seeing all aspects of the deal process from sourcing or winning the deal to closing the deal, being more involved in company strategy and adding value to portfolio companies, and having the opportunity to achieve higher returns by targeting niche sectors, spearheading growth strategies, or sourcing deals through proprietary means.