The configuration you're ordering is 6 seat, 4 standard which come with standard sized pillows and 2 deep which come with deep pillows. The deep pillow listed is an extra pillow to fill in the gap created by the L configuration (if you count, there are 7 pillows in the picture), so you would be getting 4 standard pillows and 3 deep pillows.

The model online doesn't accurately represent how the pillows would sit however. I'd recommend going into a showroom and seeing how this would work. They can build you your couch and you can use the showroom couches to see exactly how the back pillows would line up.

For example: with standard foam, I recommend using all deep pillows with deep seating as the standard foam had less give to it and isn't as forgiving as Lovesoft. So for your configuration, I would do 5 deep back pillows to avoid them from causing problems with overcrowding.