Not a problem at all on questions.
Like you've said, I think simplicity is a really big key for HQ, so figuring out ways to expand the game without unduly adding complexity has always been a goal of mine. If I wanted a lot more complex, I'd simply move to Advanced Hero's Quest or Warhammer Quest. Although I own both games, and I enjoy them, they just don't hold a candle to HQ in my opinion.
When I originally created these versions of monsters (over a decade ago), I created them independent of balance. I tried to create creatures that filled niches outside of the basic HQ monsters. So I didn't worry as much about balancing the individual monsters. I was more concerned about making something that would give a new challenge. (Balancing should be done at the quest level, not the monster level.) My general rules were:
1) Does this creature fill a role?
2) Is it interesting and add fun?
3) Does it add more complexity than fun?
Now, with that said, as I was redoing things, I have been adjusting monsters again. The Wyvern is a good example of this. Originally, I had it set as a 10 BP, 8/4 attack killing machine. I made the changes because I don't believe it needs to be that powerful to be interesting. (Those original stats were designed so that it would be more challenging than an ogre or a giant wolf.)
Now, I will admit I've been applying math back against all of these quests as I've been doing redesigns. I've been applying someone else's system to try and judge difficulty (
viewtopic.php?f=38&t=954&hilit=difficulty&start=10), but as I've recently posted in that thread, I'm finding a number of shortcomings in the system, so I'm going to try and modify the system to see if I get better comparisons out of it.