I need help with a command block chain

Ok here's my dilemma. I am trying to build a command block creation that triggers 5 repeating command blocks using the /setblock redstone_block then /setblock air. I can get the repeating to work and the second chain which is /setblock ~ ~ ~2 air but it's so fast it over rides the previous chain block which is /setblock ~ ~ ~3 redstone_block.

How do I get it so the redstone block is placed for 1.5 seconds and then gets replaced by an air block and will it be tileable? Current progress:

Solution 1:

Since a redstone timer method is allowed, here's my solution.

More information:

• The lever is the input. Replace it with your diamond block detector.
• The redstone lamp is the output. Replace it with your command block.
• All the repeaters are set to 4 ticks, apart from the one closest to the redstone lamp, which is set to 1 tick. This is required for the correct duration of 1.5 seconds.
• The piston is sticky.
• You can put any (moveable) block on top of it, it does not have to be stone.
• The screenshot is from Minecraft 1.11.2 PC/Linux (vanilla), although Pocket Edition should work exactly the same for this task.

It's probably possible to get the redstone much more compact than this, but I'm not too good at that.

EDIT: Spent about an hour compacting and writing instructions to re-create this 2x4x10 design:

It's 2 blocks wide, but you'll need to leave a space in between if you want to tile these. I'm not going to keep trying for a tileable version with no gap, but I'm sure it's possible.