Ah, well in that case, 100% you would be missing out on potential gains if you didn’t get the other intelligence fields. I think that something like drops of memory would form very excellent synergy with your Manhattan method, as well as any other brain field.
I have used almost every Manhattan Brain field from the index and they have all given me various arrays of benefits all across the board. I recommend you look into Conceptual Conglomerate to compound with your Manhattan method and you can read not only the thread of great results, but also my first post in Jojo’s Brain Journal for reference as to why conceptual conglomerate is so good.