they did lend their original out to be copied... thus facilitating dishonesty.

Sure; dock me a mark or two and tell me why. But why not just give a straight zero to the others that didn't actually do the work?

It's unjust, though, to punish those who facilitated an offence more than those who committed it.

Sharing your work to others to copy isn’t facilitating, it’s committing. Cheating is cheating.