I do think putting scenario rules into one html page will be useful, for three reasons.
First, it's easier just to open one html page and scroll around in it to find the things you are interested in, rather than looking at one page, figuring out something you're interested in, deciding which other page that might be in, opening that, being wrong, opening another, etc.
Second, it would be good to be able to open an html page of rules and print it all out in one shot.
Third, it is easier if the rules are all one html page to get all of the content and archive it or put it up on another web site. I like to archive rule sets for past scenarios I've been in. If the rules are in multiple pages, it multiplies the amount of work to do that. Also, archiving the rules is something we should do in the scenario team so that we can have a library of scenarios and full rule sets to draw from easily in the many years to come.