Reading the responses it seems that there maybe some inherent issue with monsters with HD that pump up their effective ECL, such as an Ogre at 6 versus making mosters that don't have any inherent hit dice. If for example you say a Half-Ogre would have 2HD for a total of +3ECL, that begins to sound mopre balanced to me.
I mean which would you want a Half-Ogre Fighter 6 or an Ogre Fighter 1?
It seems like there may need to be a different way of evaluating 0hd creature ECL and those that start with HD.
-MacMathan