I disagree with your hypothesis. While there may not have been a standard currency after the fall of the Roman empire, there certainly was coinage, made of gold, silver, and possibly copper.
Yes there was coinage but it wasnt as widly available since the European mines ran which made money unavailable for the lower classes. for more info regarding feudalism please visit:
http://www.britannica.com/EBchecked/topic/205583/feudalism
The idea of feudalism ,even if we disregard its origin, is of mutual dependancy do you not wonder why the feudal system almost ceased to exist as soon as the kings themself could sustain their own armies and no longer where depandant on the nobles?
My question isn't regarding it's origins but what are the benifits to the emperor himself and how does this make it an better alternative to give counts the land rather than to appoint governors?
Also there it seems like the emperor indeed appoints the counts as an in game rumor states something like this "How did a Dark Elf become Count Cheydinhal? King Helseth and Barenziah have considerable influence, and Helseth and Indarys are cronies. Get it?" Helseth hasnt been the king of Morrowind for that long so the count of Cheydinhal must have been appointed by the emperor.
Regards
The Mage