Of course that had nothing to do with GDR athletes joining the german team ...
Germany hasnt been better in the track events (at least on the womens side) for at least 25 years. Lückenkemper and Klosterhalfen are 21 years old and are the best german track talents since 1990 in my opinion. Klosterhalfen broke 2:00.00 over 800 m, 4:00.00 over 1500 m (3:58.91) and 15:00.00 over 5000 m (14:51.00) last year as a 20 year old, i am not sure whether any other runner ever did those times at such a young age. Add in Alina Reh (31:38.00 in a 10 km road race last year as a 20 year old), Pamela Dutkiewicz, Cindy Roleder, Krause, Lisa Mayer, Gesa Krause, Hanna Klein and talents like Keshia Kwadwo (4th at the U20 world championships in the 100 m this year), Talea Prepens (23.51 s with -0.7 m/s wind over the 200 m last year as a 15 year old, U18 world champion) or Marie Scheppan (52.82 s over 400 m as a 17 year old this year) and you have nothing to moan about as a german fan.
Actually Germany reached a low at the 2008 olympics and since has always been among the top 5-6 nations in the world. Poland surely got much better in the last 30 years, but of course thats easy when you were in a horrible state before. I think Poland kind of adapted the german strategy of focusing on throwing events that are clearly the least competitive events globally, while Germany started to focus more in track events and therefore lost its dominance in throwing events (although Röhler/Vetter, C. Harting, Storl, Hussong, Schwanitz, Vita/Craft are still in a good position to fight for medals in 2020).