[unknown]

demoman is more effective that the soldier at close range but at long rank the soldier is more effective so they both equal out i think.

this isn't true for several reasons
the soldier can out-spam a demoman pretty easily. in close combat, generally, the soldier has the advantage
at high/pro skill levels, i.e. solidsnake, wo0t (lol), invisible, etc, then yes i'd say the demoman wins at close range, simply because they'll find ways to hit you up that close.
far away, demoman just wins. the soldier can change that to an up-close battle by rocket jumping, but the area denial property of the demoman makes him superior at long range

remember kiddies
soldier<demoman<scout<medic