Well, consider the capability of the pack to discharge. A 3,000MaH 10C pack can discharge 30A in a burst. A 20C pack 60A. So figure out what the pack can discharge, then go above that. There’s more to the equation than just that, but if never hurts to have an extra beefy ESC. If I was hardcore into electrics, I wouldn’t bat an eye at spending a chunk of cash on a good ESC with a big Amp handling capability. Lithium batteries changed the game for sure, and their huge energy density, and capability to discharge it quickly creates the need for the rest of the system to be pretty beefy. Also ensure the wiring going TO the ESC to be beefy and use high amp connectors like Deans HV or XT60.

Just my 2¢. YMMV.