Not sure of what you mean about HOI, since there is no "reserving of units" in HOI. In SR if a base has units deployed at it you can see them. Same same for both games.
Since HOI does not have the reserve feature your comparison, presumably to clarify the question confuses me.
My mistake. Let see if i can explain my doubts better.
I meant in order for me to see rapidly where my air units, and ships are (not deployed) if there is possible to make a design or model for those air fields and ports containing units. As those in HoI (in Hearts of Iron 2, it is visible where your air units are grounded and where are your fleets by simply looking the airfields and port icons, they change either in color (if its a mod) or just a different icon design over the map that lets the user know which airports and naval bases are been occupied by their military forces.http://imageshack.us/photo/my-images/18/dibujojkw.jpg
EDIT: Ups! This is not the place to post such subject, i am sorry.