It seems Eurotrash Royals do that. Princess Grace had two weddings also. One is religious, the other is for the official record.
No they can’t. As per the law. Church of England (and the UK) has some very specific laws. Meghan thought you could just call in a minister to your backyard like in the US. This is probably why she got caught by her lie.
Had the Archbishop actually conducted an illegal wedding in an illegal setting in secret without the head of the Church knowing..which would be the Queen...it might be considered treasonous.
He certainly should have lost his job.