So they aren't exactly Flying out the door then. Might explain why the Chinese haven't taken them on.
I suspect there's a couple of main reasons the Chinese haven't taken them on:
1 - they've already got a bazillion Kubota clones in all HP ranges from 3 to 23 (ish), and there's at least 100 bazillion units already out there working their dieselly arses off day and night (often both). Developing a CS clone would be pointless.
2 - the EPA thing... China is a far more developed economy than India these days, so making a "box of bits" which claims to be one thing in order to "sneak" past certain enviornmental laws... well, it's just not worth their bother. They'll never sell in volume, unlike the Kubotalikes.
I'd quite like to import a container load of those Kubota type engines here to the UK, but I'm stuffed by the "CE Mark" legislation, which requires thousands of dollars of paperwork, reports, drawings and so forth, just to "prove" that they aren't dangerous or something, not to mention thousands of pounds of VAT and duty (all payable up front)...