Artillery Formation/Unit Signs HELP

[Wayne McGee]

I had oppritunity to look over Brad's shoulder as he was doing his research, and my take was that each battery would have;
4xSP's
4xtowed
4xquad
The above x3
This would give the most flexible mix of AADef, most likely, but not neccassarily, doled out to the Brigade Comds(1xBty ea).
....did that make any sense...if so, can you explain it to me?

Cheers

Wayne