Draft a good contract, let the governing law be Kenyan, get a Company profile & portfolio of business, ask for bank records & known assets,
if things go bad, sue, threaten to sue, also threaten to involve immigration department on the matter, as most of them are on questionable Visas... have no work permit.
Have close relations with High Commissioner/Ambassador, have a Contact with an independent Chinese Contact in China who can follow up on matters in China too.
Let me know if you need help on any of those.