I agree, it's a cool strategy. I didn't come up with it; it seemed brilliant at first, so I posted it. Only later did it become clear that it wasn't reliable, but I was too lazy to change it.
The richness of the template has absolutely no effect on the number of gnolls. 42 is the average number at the start (2 stacks from the native heroes and a few more in the castle). Of course, if you give 7 gnolls to the weaker heroes, you'll be left with 35. But I almost always build snakes on the first day to speed things up, even if the lizardmen haven't been built yet.
http://www.youtube.com/watch?v=NJ_WPP-js0s
Here's an older, more reliable strategy. But I only tested it for Tazar; I can't vouch for other heroes.
And honestly, is it really that hard to try it out yourself? When I created this thread, I was hoping for a collective discussion and improvement of the tactics, but unfortunately, no one has offered any intelligent ideas on this. Only "do this," "do that," "and I have this whim"... As if I'm a professional inventor of tactics for the Necropolis. I created these tactics for myself; I just decided to share them with others. And I'm quite satisfied with what I've done. In short, I don't want to bother with these Necropolis strategies anymore. If you're interested in something more, do it yourself and post it; you'll get my respect ;)
42? At the start? You must be joking, brother