It's not "broken". It is merely because the poole of characters is so much smaller the shitty odds are more apparent. These are the same odds you have with any "rare" soul... you either get lucky.. or you get the same lower-end characters all the time. Heck, I've dropped 99 Heroic souls and NOT gotten the top 2 featured characters there..... the odd have always been fairly crappy.

As for these... yes all shardbornes and onyx sons with the occasional golem... but I did have G and M Minotaurs drop once each as well.