Ed,
The batch you quote is a list of patron submissions from many parts of the country so its data should not be accepted per se.
You may have noticed that there is no verifiable source document given against any entry so they cannot be verified easily. Your alleged accurate entries gives no credance to the othe hundreds of other entries.
Many of the submitted entries in the IGI relate to baptisms for the dead and if, prior to data submission, the LDS member had found the data in an extracted batch, after the LDS ordinances had been performed, the entry in the extracted batch will have been deleted but not all submissions were once extracted and given in batches.
The site
http://freepages.genealogy.rootsweb.ancestry.com/~hughwallis/IGIBatchNumbers/CountyWiltshire.htm#PageTitle gives the remaining IGI entries which were extracted from church records and are acceptably accurate extractionwise.
But the LDS have batches of so called extractions not in the HW site which must be found by using common names in IGI searches. One then needs to establish if they are extracted. If they are extracted, are they already in the HW site? For example, I found batch C160831 baptisms and M160831 marrriages at Broad Hinton WIL may be used in HW site but no reference to them can be found in the LDS library catalogue. I wonder which catalogue LDS members use?
Regards
Chas