@zanthor:

Thanks for translating into german.

Kriwi already explained to me what you've tried to say in your post.
Now I finally understand what you've meant.

Thanks to zanthor and Kriwi because my fuse can't handle 5 PCs so I have to setup a multiboxing system on 3 PCs

As soon as I got the hardware I'll try that "horizontal span" thing.

is there an option for a vertical span? Because the TFTs will be
fixed on the wall in two vertical lines and the main TFT in the middle.
(I can't look by myself because I don't have the graphic card yet)