As perhaps a "simpler" tweak for HD, would be just using the D3 template (teams, locations etc.) but bumping the recruiting budget to equal D1 recruiting. That eliminates baseline prestige right there too. They you still have the same recruit generation just the D1 level recruits rarely get taken and you eliminate the EE headache.
Of course, there would be no firings, but without baseline, do firings really matter?
To further simplify things for WIS, the world is a "hidden" world. It is only visible to IDs meeting the eligibility requirements under that ID. Plenty of websites have exclusive sertions that only open up if you qualify (i.e., have sufficient posts, become a paying member, etc.) so the coding must be pretty straightforward.
Thus, HD can use the same engine and only have to adjust the recruiting budget if people wanted ther D1 recruiting aspect.