With social media and a lot of social marketing it will compete with Alibaba...I think what you need is you have to find what is lacking there and apply in it.
I think you need a strong personal network of people and companies in south asia to successfully launch this kind of business. B2B is all about relationships, particularly in places like South Asia. If you have this kind of network in place or believe you can realistically develop it over time, then the sky is the limit in terms of potential opportunity for a b2b ecommerce start-up in south Asia. With such a network you can compete effectively against Alibaba.
As it pertains to entrepreneurship, it is simply taking a calculated risk. With that being said, the question should start at: "Which problem can I solve that Alibaba isn't solving yet?" .
The bigger the problem is, the better your position against your competition. Try looking at it from that angle first and then move to the "how".
I suggest create a whole new drop shipping business model..