At most levels it's probably overkill.
Our coaches were getting frustrated with missed signs so we started doing this as well. Attached is last years offense (flip side is defense) but its about as basic as you can get and the girls pick it up much easier. The multiple number/color combinations makes it very hard for opposing teams to pick up as well.
Here is our one from 8U awhile back.
Hope this helps
I am always amused at how much time and effort some coaches put into their signs. My DD's HS coach is one of those baseball guys who will give a sign, "wipe it off", then give another sign, wipe it off again, then give another sign as if the CIA and NASA are trying to crack the code....he spends 15 seconds between every pitch giving signs. I need to get some video of him giving signs and make a music video with it!