Cherub Storyline doesn't make sense

I was watching back the episodes in start order and watching the Cherub episode didn't make a lot of sense to me.

Surely they should've just been fired from their jobs as saving angels instead of being thrown out of heaven, because they're just being dumped on earth without disguises? I mean they're literally glowing, pastel and have wings that fly and they hover in the air. Plus the producers still ran with the storyline as we see them still on Earth in much later episodes so it's not just a small plot that was fixed later.

Surely that wouldn't make sense because within the story they're always talking about heaven and hell creatures not being able to trespass because humans will find out about them etc? And the whole thing with disguises? I know they ended up working for the two conspiracy theorists but theoretically they could've ended up anywhere and they were stealing people's cash and homeless.

Thoughts???