Bloodbowl cheerleaders are orks in drag. They saw that all of the other races had cheerleaders with long hair and bumpy-thingys on the their chests so their cheerleaders wear sqwigs and stuff their shirts.
The orks are all hairless. There is a specialized squig called a 'hair squig' that has a remora like mouth and long hair-like gills. They are parasitic, sucking blood from their host to survive. The orks style them to taste and latch them on. Seriously, I'm not making that up.
I've not read the thing about ork females locked in a tower but I won't deny it. I haven't read the first ed ork specific books because back then I had a marine and guardsmen mix led by a rogue trader and his squat lieutenant. I did have an ork playing friend who told me that it was widely believed that the snotlings had been the brain boyz. Their minds were enhanced by a fungus that they forced the orks to harvest. One day the orks revolted and ate the mushrooms themselves, becoming stupider in the process, then forgot how to grow them. The snotlings also became less intelligent from lack of the special mushrooms. No longer posessing the brain to overcome the brawn they themselves were enslaved.
Of course, back in those days the tyranids all looked like termagants and they rode around on rhino/centaur looking creatures called Zoats. Games Workshop is certainly creative in their fluff, but they frequently change it to suit their current tastes. Excuse me, I mean to say that new evidence often disproves outdated Imperial Xenological Theory. Of course, someone usually dies for heresy when it does.