My room is quite a bit different and employs the 20.1s so I am not well qualified to comment on your situation other than to say that I agree with Magfan that it seems to be best with the tweeters on the outside. I tried it both ways and prefered them on the outside.
Also, the advice to make SMALL changes at a time is good advice.
Also, the advice to make SMALL changes at a time is good advice.