Like Sypder said, you can do whatever you want to keep a healthy lizard, it's all in how you manipulate cage conditions.
However, caresheets are typically geared towards people like you, who have never kept one before. Sure, you can try using less soil, or no soil, but you're not going to be as successful as quickly as you would with a nice thick soil substrate. If you've never kept ackies before (which it sounds like you haven't), stick to the simplest formula that has worked the best for the most people at your experience level. After you've kept your animal for a while (as in at least 6 months, if not a year!) and are familiar with its habits and needs, start tinkering with cage design and substrate if you want.
But, you'll probably find that the formula recommended is indeed the easiest and most successful way to keep them.
Breeding or not, the setup tends to be the same because in order to keep them as healthy as possible in a pet capacity, you end up keeping them in the same healthy condition they would need to be in to breed. And of course we all want our pets to be as healthy as possible, right? 
There's no shortcuts when it comes to keeping monitors. You're going to the effort to block up the screen top, what's so much more difficult about soil substrate?
Good luck!
~jen
-----
"We call them dumb animals, and so they are, for they cannot tell us how they feel, but they do not suffer less because they have no words."
- Anna Sewell (1820-1878)