Instead of doing this, I would purchase a full core, and put 5 colors of core on two rods. I would also pick up some 4oz Dive Bombs. With a 4oz Dive Bomb and 5 colors of core, it is the same as a full core.
MiStinger came out with the Dive Bomb last year. This is an add on plaining weight. A 4oz dive bomb on mono will get you around 30' down.
Some of the other things you need to know about lead core.
One color of lead core will get your bait 4-5' down.
A half core is 5 colors - this will get your bait down 20-25'
A full core is 10 colors - this will get your bait down 40-50'
On top of the 3 riggers, and 2 divers, I run 3 inline planer boards off each side of my boat. I run a full core, half core, and a 2 or 3 color core off each side. Always keep your deepest(The one with the most core) closest to the boat and work out. I also run a 2 color with a 4oz Dive Bomb, right down the shoot for a 12 rod spread.
When setting lines, you can run the half core and 2 or 3 color straight out the back, hook on the board, let the board out behind the full core, and work it to the outside.
With my spread, I am covering the 40-50' deep, 20-25' deep, and 8-15' deep. I will also add Dive Bombs to my cores, to get them in the 70-80' depth. I have found through trial and error, that you should only run a dive bomb on your inside boards.
How do you end up with different size cores? I have started out with several full cores. After a few tangles, the end up shorter