Hi, luupainaja!
To be completely honest, I am not sure how the calculation is done. Following the logic, if we have somebody/ies covered, we can take the bounty for their knock out, therefore we can loosen up our range. Unfortunately, I am not quite sure how to break down the math.
Maybe you can forward this question to one of our knockout players such as superuorme? ClickHe has a blog here in the english community. He also has a solid background playing these games and I think he can be more helpful than me in this area.
Cheers!