Minato stated that Kurama's chakra was too much to seal into a newborn, even though it was an Uzumaki. However, Rasa, the 4th Kazekage, sealed Shukaku (probably the 3rd strongest tailed beast) into Gaara when he was just a fetus, which should've caused a miscarriage if we follow Minato's logic.
What's the difference? Was Rasa better than Minato at sealing techniques? Or is it just a plot hole?