Shumenov is garbage. His best win is over a starved Uzelkov, and he got an absolute gift ober Campillo to win the title. For the most part, his stamina is poor, he doesn't have that much power, and is defense is vulnerable to speed. I'd pick Cloud by decision based on his activity and speed, he could overwhelm Shumenov.
Shumenov has all the tools to become a good boxer technically but I don't know if he will go in this way. He needs polishing. He is really brave, has heart and is a real warrior, he is also tough as hell. Right now I think it's 65\35 Cloud but I don't think much of him, he reminds me of Jeff Lacy.
Shumenov is still green as ****. He's showed massive improvement in his fight against Uzelkov and I expect to see more improvement.
Shumenov, and more recently Rigondeaux are examples of why you need a decent number of professional fights before stepping way up in class. It was too early for him to be fighting Campillo, I know these guys have amateur credentials but its a different type of fight. If he takes his time he could be very good, but right now Tavoris simply overwhelms him, in about 18 months I could see that changing.
If it was Cloud who caught Shumenov in the 1st round instead of Uzelkov then it could well of been lights out for Shumenov