What do you do differently from Stellar or Ripple at the consensus layer which both started out with similar ideas, but quickly found that their validators fall

What do you do differently from Stellar or Ripple at the consensus layer which both started out with similar ideas, but quickly found that their validators fall apart due to the strongly-connected validator set requirement not being met? In other words, how do you avoid the exact same fate that both Stellar and Ripple ran into in their consensus models when they also tried to let "node individually choose"?