Got so many alternatives to WTC but only post only the one with
majority HC bus service. Granted, the only other option is Svc 950
which is likely full from WDL, but there are options from nearby
stations
Kranji: 160, 170, 170A (Terminates at WTC), 170# (Starts from
Kranji), 178, though most might arrive full at Kranji, and all of
them are full SDs.
WDL: 178, 856 (Cfm can board), 911, 913, 950 (Cfm can
board).
Also take into account that these pax boarding Svc 856 are also
heading beyond WTC towards Marsiling/Senoko (Areas not covered by
Svc 169).
Also this one is during peak hours, possibly max frequency and
HC buses deployed during that timing.
Ask him visit Sembawang MRT during 9pm-10pm and see the crowd
waiting for Svc 856, at 10-15 mins freq, only to kena SD and full
from Yishun liao.
Just to clear things up, 170X (or you 170#) does not go to WTC
unless one comes frm malaysia and walks there. lol