Well, only having seen one episode of
Souten Kouro, I would say that looks very similar. And I'm quite surprised to see one like Souten Kouro so soon. I mean, only one season or so...
Though bad thing about Souten Kouro is that only 12 episodes have been subbed by various groups and unless Romance of the Three Kingdoms gets subbed by a reliable group, there's going to be a long interval between episodes. And of course unless ROTTK is even better than Souten Kouro.