Problem with both Prussian and Japanese models is that they involved large military aristocracies. I don't see that happening in Caldari the way it does in Amarr.
While I would agree the Caldari don't have an aristocracy they do have powerful shareholding Executive families that have a great deal of influence over the Megacorporations.
This might be a bit of supposition, but I've also sometimes seen the Deteis as being the de facto aristocracy or something a bit akin to the Prussian Junker class. Whilst they might no longer own land in a feudal society, the Caldari do impress a great deal of cultural conformity and the latent expectations for the Deteis in the State seems to be that they seek to fulfill Leadership roles in the State. The very racial description of the Deteis, if seen as the stereotype, is that they are expected to be ones who manage affairs, who become the managers, the executives, the officers and the General Staff.
Also, when looking at Caldari history when they went from a "Warlord era" when the Gallente implemented the Cultural Deliverance Society to a corporate society in a short amount of time, if those Warlords were say, a small military aristocracy of Deteis with a large soldiery of Civire then that same sort of dynamic might very well be a strong cultural trope remaining in the State: Deteis lead, and Civire follow orders.
It's also amusing when one considers that Tibus Heth was a Civire railing against the "corruption and nepotism" of an entrenched ruling class in State society and that those primarily opposed to him and responsible for his downfall were Deteis like Haatakan Oiritsuu, Admiral Yanala, and Mens Reppola.
It's also that for some reason it's just felt right even from my experiences in internal RP with Caldari: Veikitamo as a Deteis does the proper thing of seizing power and authority for the Greater Good, and the Civire like Desiderya and Pieter might have issues with her Machiavellan scheming at times but in the end that's just Caldari and the way things are done.