My mum & dad used to actually argue about this.Everyone does know that Yorkshire pudding is a starter, right? You do, don't you? With gravy? Whilst waiting for the man of the house to carve the beef (if he can still see straight)
He, being a Yorkshireman wanted it before the roast. My mum, being the person cooking it, would do whatever the fuck she wanted, & served it cut into sort of corner pieces on the plate with the roast on top.