Actually if you really follow the history, Nanyang University with all its resources was merged into University of Singapore into NUS, that is why NUS logo has Nanyang University logo of the 3 circles. Its died on Lao Lee hands, if there is any real link.....it has stronger links to NUS than current NTU. Only in 1996 alumni rolls of Nanyang University is transferred from NUS to NTU.....
The current NTU has no real link to Nanyang University. it is developed from merger of NIE and NTI (which was then something like a college of NUS for engineers) which was initially used for training teachers and engineers that Singapore badly needed in the 80s. There is no real continuation from the earlier Nantah. NUS transferred its business school in the late 80s (which is a dumb move as they later have to spend time to rebuild a totally new business school from scratch) to NTI and leads to it being promoted to the status of a technical University. only in the mid 2000s I believe with the introduction of medicine etc, finally we have the 2nd full fledged university.