pardon this non-native, but shouldn't "We are looking for two students that are studying language pedagogy." be "We are looking for two students _who_ are studying language pedagogy." or possibly _which_ ? Or are they equivalent?
'Which' wouldn't be used here because 'are studying language pedagogy' is restricting/filtering 'students', and so it's essential to the meaning of the sentence. 'Which' is used for clauses that add non-essential information.
My shirt that is red is upstairs.
My shirt, which is red, is upstairs.