Stats only tell part of the story. To me a top FC spinner should be able to do the following things
1) Rip it. Not roll the fingers but genuine rip so that the ball spits off the surface
2) Loop it. Variations of flight and drift. Ability to toss the ball up above batter's eye-level and get batter to lift his head and then beat him with dip, trajectory, etc.
3) Variations of pace. Be able to mix up the speed and keep the footwork of the batsman honest
4) Variations of spin - sliders, arm balls, carom ball, wrong 'un, etc.
5) Courage. Lots of courage. Throws up the ball after being hit for a six
6) Patience. Spend over after over setting a batsman up for that one mistake.
When I look at the names you have listed, Shuvo, Arafat and Razzak immediately don't make the cut. As I mentioned in another article - their success owes much to our FC batsmen's impatience and lack of technique with the low bounce off the pitches coming in as 2ndary.
Saqlain is a great flighter of the ball. He's better than Shak in that regard. However he doesn't rip it. That's why he gets hammered when he plays against international A-team players
Sunny is the real deal. Rips the ball. Great control of flight. Problem is that he doesn't have a lot of variations.
Shak is a smarter and more intuitive version of Sunny. Hence his success in the international arena. He of all BD spinners has bowled some big league jaffas.
Enam had all of the attributes except for #6. He would try to hard. I think he's getting better on that and sooner or later he's going to break into the side. He's the McGill to our Shak Warne
Overall, all our spinners are weak on variation and rip. And most are weak on how to use flight and not bowl flat darts onto the pads.