In Batcheller’s descriptive picture of Dover Castle’s Church, it describes 'the arms of Lucius' becoming ‘effaced by time.’ However, the arms of Lucius which were once part of a ‘magnificent church’ clearly became less important over time, suggested by the neglect. This proves that the neglect of Dover Castle, and its grounds, in the 17th century might not have been an 'anomaly' as described. And maybe it was only adapting for new and different uses e.g. becoming a prison. In fact, Coad contradicted himself at this point. He stated that Dover Castle was also used as 'prison well into the 18th Century', meaning that it wasn't necessarily neglected; as it could function other potential uses such as trade, communication, honour, and occupying a prison. This means its military purpose wasn't always needed.
Batcheller does agree with Coad’s interpretation; however it can also oppose it. A report in 1727 (early 18th century) describes the castle to 'have suffered much, both from neglect and violence'. It also wasn't until the end of the 18th century, that £50,000 was spent to 'secure and defend this important military station' from the 'continual threats' of a French invasion. This suggests that Dover Castle was being neglected. However, opposing this idea, it may not have been neglected, just inactive. 'Defences here were to be strengthened in every subsequent European war in which Britain was involved.’ Meaning that it was only needed to be re-strengthened when threats of war arises.
The Elizabethan accounts for Dover Castle describes it being 'almost made up entirely of items of renewal or replacement.' This tells us that it wasn't just the 17th Century Dover may have been neglected. So it may not have been such an ‘anomaly’ If it was left to the point it needed these last minute repairs of 'renewal or replacement'. However, in relation to this, the time period here talks about Dover Castle in the late 16th Century (1596) which isn't far from the early 17th Century (when Coad describes its neglect as an anomaly). Although, contradicting that, it’s still a different time period from Coad's point about neglect.
In conclusion, I’d say Coad's interpretation was correct about Dover Castle being neglected during the early-17th century, but not as an 'anomaly' as Coad describes it. This is because there is evidence for it becoming neglected in other time periods. Or even that it was just adapted for different uses (e.g. a prison). You also have to remember that his interpretation is an only an opinion, which isn't necessarily factual.