Imperial Regiment organisation

Hello, i understand that a smilitar topic had been already discussed but i had yet to see anyone talking about the logistics of single imperial regiment. In my love for the guard i had gotten interested in the structure of modern military units and from what i understood, in a single regiment, about 70% of people are active soldiers. The rest of them are logitics personel. I know that in books the cooks and medics are present, i understand that much of the technician support is done by tech priests assigned to the regiment but they are never really included in any overview of the regiment.

For example, there is an example of a four thousand guards in a typical cadian regiment (if memory serves me right). From what i had seen those four thousand men are all active duty soldiers. Unless some of these soldiers are also part of the logistical units, then these active men need about 1800~ poeple in logistics.

So the real cadian regiment would be about 5800 people. Do i understand that correctly or am i wrong?