How do subaru boxer engines stay lubricated so well if the cylinders are 180 degrees?

The oil return holes from the valve cover area must be near the bottom of the engine's head. Otherwise oil would pool in the lower valve covers. VW Beetle engines were the same way and I never stopped to ask the same question. One advantage would be less oil draining down through push rod valve seals into the cylinders. I can understand the crankcase lubricating the piston rings. I guess when you have an oil pump and 20 psi oil pressure you can spray oil wherever you want to. But it has to drain back down into the crankcase from the heads.