There is no advantage to naming the same school more than once as this does not increase your child's chances of of being allocated a place if the school is full.
In addition, if you list only one preference and this is not your catchment school, we cannot consider your child for a place at the catchment school until all other applications for that school have been processed. This may result in your catchment school becoming full before your child's school placement can be considered and your child will then be allocated a place at the nearest appropriate school with a place available.