5 or so should be enough. If i didn't remember wrongly, the
standard display only allow you to hand 1-2 sets of number 4 and
the rest must all be folded neatly anyway so hangers are only used
during normal times. Most people can't be bothered to keep refold
uniform when going standby so just don't hang.
Now sure whethere any changes in the display format and might
depend on how strict your specs are with it cos mine were pretty
strict in ensuring we follow every single detail in it.