Do you also know how they allocate across all three of the choices? In other words, if my daughter has Queens first and clever clogs has Parmiters, Grammar, Queens, and they miss Parmiters and Grammar but score higher than my daugher who has put Queens first, will they get the place ahead of her? Or does the fact we've put it first count for anything?
The schools allocate without knowing your preferences. For example, Queen's are given only the complete list of applicants who listed them anywhere in their preferences. They put these in rank order according to the test. (They will also have separate ranked lists for sport, music and distance.) They forward the top 92 names on that list to County, offering places. County inform them of which of those names have been offered places at schools they ranked higher, and Queen's reallocate that many places, working down the list in rank order. This all happens invisibly before allocation day, though it continues afterwards if some places are turned down (say to go to a private school).
So cc's place at Queen's won't be freed unless he/she gets a place at Parmiter's or the Grammar; you would gain no advantage by putting Queen's first. The only reason to depart from one's true preferences is to include at least one safe fallback.