Getting the facts right

A recent article in the Observer led with the claim that: "Hundreds of senior staff and management have left the Prison Service in the past five years without being replaced". Their evidence for this included that: ‘[over the last 5 years] there were 205 outgoing managers compared with 23 incoming, while only a single replacement was hired in place of 295 custodial managers’.
I may have got the wrong end of the stick here, but while we all know there’ve been significant cuts in staff at all levels, and that these have caused significant problems across the service, I’m not at all sure these particular data support the article's central claim - ie that there’s been a huge decrease in the number of operational managers in HMPPS over the last 5 years. At least of late, the prison service has not generally recruited directly to operational management posts and instead has typically promoted from within. So we’d expect to see few operational managers having been replaced from outside. I’m not sure therefore that it’s a surprise that: ‘[over the last 5 years] there were 205 outgoing managers compared with 23 incoming, while only a single replacement was hired in place of 295 custodial managers.’ The implication here is that there are now 294 fewer CMs and 183 fewer senior operational managers now than in 2013, but unless the article is badly worded, I don’t think that’s what these data actually show - and I’m not at all sure that that is the case, although the published workforce stats don’t enumerate operational management levels separately from the rest of the workforce, so I may of course be wrong. Can anyone enlighten us?