If there are very large amounts of money or very risky behavior involved (e.g. behavior that could trigger an investigation by a government agency), it's sometimes worth paying for the best of the best, so you can avoid any questions along the lines of "why did you use JoeSchmoe's RubberStampsRUs Consulting, when you could have used one of the big firms?"
I’m not sure who the rubber stamp would be for either. Your subordinates I guess? But that seems not particularly important tbh.
[1] https://www.cnn.com/2024/04/25/politics/mckinsey-justice-dep...
[2] https://www.npr.org/2022/10/03/1126202801/mckinsey-consultin...
[3] https://www.nytimes.com/2022/09/30/world/africa/mckinsey-cor...
[4] https://www.newyorker.com/news/news-desk/mckinseys-work-for-...
I urge you to consider the ethics of your current employer and consider seeking employment with a different company.