That is a fair summation. The legislation is currently worded to say that you start at the top and work down; the reality is that most polling district reviews are based on working upwards, based on the availability of premises. The key point for any review of polling districts is that the locations—the polling places—must be accessible to the majority of electors. In the case you have described, the decision, which was presumably made by the local authority, is that there are two good venues with good accessibility, so it would make sense to use both venues in that situation. In other cases, there will be a surfeit of venues, making it far more difficult. It really depends in many respects on what premises or locations are available. In some locations you see temporary buildings, such as portakabins and caravans, because there is physically nothing else for returning officers to use.