They're smaller than the carabao. Which could mean they'll less efficient in farm works. How about its reproduction rate?
The size :
This drawing shows the extinct dwarf water buffalo in proportion to the tamaraw (a rare dwarf water buffalo that lives on the Philippine island of Mindoro); a full-sized water buffalo; and a human being. From
http://blog.case.edu/case-news/2006/10/17/waterbuffalo
The adult female tamaraw gives birth to one offspring after a gestation period of about 300 days. There is an interbirth interval of two years, although one female has been sighted with three juveniles. The calf stays for 2–4 years with its mother before becoming independent. Another problem comes from the fact that tamaraw is a solitary creature. They don't live in herds or smaller packs and are very fierce. Although some behavorial studies, found some specimen in groups, sized from four to six.
The origins of the domestic water buffalo types are debated, although results of a phylogenetic study indicate that the swamp type may have originated in China and domesticated about 4,000 years ago, while the river type may have originated from India and was domesticated about 5,000 years ago. The present day river buffalo is the result of complex domestication processes involving more than one maternal lineage and a significant maternal gene flow from wild populations after the initial domestication events.
How about cross-breeding with the carabao?
Technically possible, both the tamaraw and the carabao are swamp buffaloes. Trivia : The swamp buffalo has 48 chromosomes; the river buffalo has 50 chromosomes. The two types do not readily interbreed, but fertile offspring can occur. But the size difference could be a problem ...
Where do the tamaraw come from? and is Mindero the Island of Ma-i, as related by Sung dynasty?