I tend to focus on one over the other. For example, right now im doing starting strength to build strength up in preperation of going into the Oly lifts full time. To keep fairly fresh in Oly work, my warm-ups consist entirely of practicing all the balances for 10 - 20 minutes. Heavy form work mainly.
So if you wanted to focus on SS for a while you could do so without sacrificing much Oly work.
Another good way to go for fitting in 4 dys a week might be doing SS M/W/F and fitting in a light Oly Day in the middle.
But um, Greg is the master at this so maybe he could chime in.