There was an option to strategically move units in HOI3. IIRC, all you had to do was select the unit(s) you wanted to move, shift-click on where you wanted them to go, and then select "strategic move" or something to that effect. It was a lot faster but it made your units non-combat ready, which is realistic. My interpretation of this was that you just loaded your troops/equipment onto trains/trucks and shipped them to wherever you needed them.
As far as I know, this or something similar will be implemented in HOI IV. I can think of no logical reason why it would be removed.