Both SA and England stuck with lower-order batsmen: Lack of Aggressive Bowling?

I realize that saying so would mean undermining the usual tenacity shown by the Proteas bowlers but the fact remains that England was able to save the first test match purely due to the inability of the South African bowlers to dismiss the late batting order of England. For starters, they allowed Graeme Swann to make a half-century and give England's total
a sense of respectability and on the final, decisive day of the test match, the South Africa bowlers just kept bowling outside the off-stump or so short that the ball never made an impact. I was wondering what happened to Ntini and his ilk who would get under the batsmen chin and in their toes as soon as the number seven onwards batting of the opposition took stance against them. Is it just lack of intensity or are the bowlers bowling too much of the regular line and length type bowling? The same holds true for England in the second test match against South Africa. They could have easily restricted South Africa to about 270 but then Steyn took over and carted the England bowling to all parts. Stuart Broad kept bowling what is generally regarded as the conventional, decent line, without trying to bounce out Dale Steyn. I believe England are missing someone like Harmison and Flintoff whose height and overall bowling style made them a headache for the lower-order batsmen. Onions and Anderson merely kept on pitching around the good-length area without trying out the slower balls or yorkers that are becoming so useful these days, considering the amount of ODI and T20 cricket being played…just strange!!