In unifying three different systems, it was obvious that the different nature of "han", which were governed by chihanji and hanshi unlike "fu" and "ken" that were governed by the government officials, became the biggest obstacle for "sanchi-icchi".
3つの形態に分かれた機構を共通にしようとすれば既に中央政府から派遣された官吏によって統治される形式が採られていた「府」・「県」とは違い、知藩事と藩士によって治められた「藩」の異質性・自主性が「三治一致」の最大の障害となることは明らかであった。