Mark Owen was in TAKE THAT! You dont get much bigger boybands than that. So no way was Ziggy as famous as him.
Kenzie was known amongst most girl teenagers, and I knew him cos my sister was obsessed with him.
H was in Steps- the kings and queens of cheesy tack, you didnt get much bigger than them in the 90s either.
Ziggy was in Northern Line
So no he couldnt have been in CBB imo