Its not that simple. You can only connect the first and last layer of sticky pistons with repeaters and redstone. But you cant connect the two layers in the middle that way. Thats why i was trying to use the redstone blocks... Does anyone have a way to activate all of the 4 layers ?
The concept is to place a block layer of redstone torches below the pistons. Then repeat that process while doing 1 row less for each layer until you get to only 1 row of redstone torches left. Copy the position of the delayers and redstone, if you know how to turn off torches im sure you'll get how that works. Off each section of delayers, place to blocks to either side, place redstone, and then a torch off the side, this is what corrects the output of the pistons to be all the same.