This guy, while incompetent, had his personal email hacked.
Important distinction.
On the other hand, Patel's emails "appear to show a mix of personal and work correspondence". We already know that people in government - this isn't a partisan point: folks of all factions do it - use private communication channels to discuss "official business" specifically to avoid mandated disclosure and archival requirements. If (and I emphasize "if", because we don't yet know if this was the case), if Patel was doing that, and especially if he was sharing / discussing classified material, then the facts of the case would bump right up against what Clinton and Powell did.
Trying to distinguish between the two acts is like splitting hairs on the same arse.
Just makes you look silly.