I think any single item of religious clothing, jewellry etc should either be banned or allowed because despite the notion of it not being 'necessary' to the faith, it becomes a long drawn out legal argument on perception. I don't believe that the turban and headscarf are considered necessary parts of a religion but it seems accepted practice to consider them so. Some of all of these items are simply cultural, tradtional or preferred by the wearer.
Get rid of them all - they have nothing to do with practicing your religion freely. Do your job, go home and dress, study, preach, donate, teach or otherwise live within whatever religion you choose.
To abolish the cross on a couple of women is simply prejudicial if you aren't willing or don't apply the same restrictions on everyone else for the same reason. It appears there were other people wearing their symbols of faith who did not receive the same treatment. sammies