[Tenzen12]

That's not accurate. Noone knows who is Jack or what their state of mind was (and loli Jack is just one of possibilities that throne of heroes can manifest). Being "embodiment of madness" is about all that paranoia, fear and general atmosphere of London at that time, then person themselves. That said human perception of heroes warp them (that's why for example Vlad got that vampire thing going for him despite never being one in life) so servant Jack would be insane if he weren't summoned as Berserker.

To put it simply, noone knows whether Jack the Ripper was insane person, but Servant Jack the Ripper as embodiment of insanity will be always insane unless it's summoned as Berserker in messed Holly Grail War where rules are more like guidlines then anything anyway.