Neither gasket should leak.
Over torquing the bolts is the main cause, followed by poor surface prep.
I just use RTV on the valve cover after good prep of head and valve cover. Many like to use "Gorilla Snot" and glue the gasket to the cover, then just a thin skim of RTV when torquing it down. The guys that use the one piece oil pan gaskets really like them, I use the standard 4 piece set with RTV in the corners. It doesn't look bone dry, but doesn't drip either.
418 miles on 19 gallons of gas. Can't beat the BBD !