Why? I know that's how Hattrick works, but other than that, I don't see why one would assume this.
That has nothing to do with Hattrick. If anything, half of my post in the How Did I Lose thread are spent to explain to people that half 1/3 level difference in team ratings really doesn't mean as much as they thing.
One doesn't have to assume anything. Even if you haven't followed the forum discussions with the BBs on this, since they're few and far between, there is a nice quote from the rules in the previous post in this thread:
(46657.86).
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."