Heres a little idea ive developed.
Layout 1
This is how my two 21” screens are setup. Now that you know this I decided that scrolling across the entire span of 3360 ( or 1680 x 2 ) pixels would actually be slower then stacking the screens as seen next.
Layout 2
Now even though my physical setup isn’t like this I feel its simply better because of the span of motion you would have to do and also the more space that is connected between the two.
System Preference
Perhaps if I get aggravated (goes against common usage or muscle memory) Ill switch it back to Layout 1.