1st ed. was like that for tournament play. OD&D (brown books) wasn't all crazy like that. I'm pretty sure Chainmail wasn't that crazy either. It couldn't be, it was wargame scale.
Also, wasn't Chainmail just a medieval wargame, and it was the brown books which added the fantasy element? I don't have Chainmail.
Edit: wiki says there were two books. Chainmail, and the "Fantasy Suppliment".