Se is about movement. Movement occurs through the sequence of time, moment after moment, from past to present to future. Therefore Se seeks Ni.
Ni is about sequence of time, moment after moment, from past to present to future. But this is pointless without movement. Therefore Ni seeks Se.
Si is about ease. Getting maximum ease requires inventiveness and this is obtained from Ne.
Ne is about suggesting improvements. Ne seeks Si to implement the improvements.
Te is about extracting the most productivity from people but needs Fi to ensure people are treated as people rather than machines.
Fi is about maintaining good relations, and seeks Te to make something productive come out of those relationships.
Fe is about expressing emotions but needs Ti for gaining objectivity.
Ti is about objectivity but needs Fe to unwind.