Sorry, but I can't see any resemblances...
Well, I know that the helmet isn't maybe egnough open (and the beard is only a matter of time), but except that, what do you think doesn't fit ?
I think it is what we have the best that can look like Leonidas looked. If you are not happy with this one, you can still make your own. I don't want to look like someone who isn't able to take negative critiscism, but personally I think your comments is usless. You do not give any clue on how doyou think it can be better, you only said that In your opinion, it doesn't look like the leader.
Someone at Civunited (sorry, forgot his name) already told me that the helmet should have been a bit more open to match the helmets that spartians were really using. His criticsim was really contructive because he added a point. Unfortunatly, I already spended a lot of time on the helm and I still have others things on my to do list (and I do not have a lot of freetime, 3d modeling isn't my job so I can't spend a lot of time to it) so I think it will stay like this (except for the beard that I will add probably this weekend). Personally, I think it match the representation of a Civ4 Leader of Leonidas. I mean, there are a lot of others LH that doesn't look excatly like their model should have look like. If the Friaxis artists took some liberties, I do not see why I can't, even that I am not paid for this.
If you really think that Leonidas deserve a better art, and you aren't able to give some constructive comments on the artistic production of other, than you just have to create your own leader, I made some tutorials on the subject.