Seem like Bart cannot survive out on his own. He has exhausted all means-from cheating, bullying, manipulations, but he still failed to attain his last ultimate crown.
Even his most recent talented loyal Matija, whose had such an amazing portfolio couldn't do much in his quest (remember Matija formed his own kingdom and give Spartans a farm war). He come to realise this is taking way too long. Matija all along, just a follower under BB true leaders. His crown experience as a follower to Bart is useless.

So he decided to join Sleepy (7:6) which boost a much better quality of crew compared to Matija. Let see if he is able to crown this age. Let's wait. Foresee more foul plays coming out while Bart tag team with coss.