Yes, Lexisgranny, in my experience vegetarians don't want the same as meat eaters, but without the meat . Lovely as the accompaniments can be, they are not the meal, and it can make guests feel like afterthoughts if they are given extra sprouts to make up for the lack of turkey.
I also found over the years that a completely separate veggie 'option' can be a bit disappointing, too. If you get lasagne, for instance, and everyone else is tucking in to a traditional Christmas Dinner it's just not the same, and they don't really work as a mix and match. This is why I make a roast of some sort, and then everyone can have the veg, the roasties and the cranberry and bread sauces. Vegetarians enjoy Christmas Dinner too.