So if they would want to HIDE ca$h offshore, would they use easily identifiable names like Jehovah, Watch Tower, Jw.org etc in the name of their shell company? I didn't think so.
Even if the WT would do the dirty work of creating the offshore companies themselves instead of using an outside expert, one would need to know which people inside the WT would most likely be responsible for creating the offshore companies and search for those persons instead. But knowing how tight lipped the WT is about their finances, its very likely that nobody possesses such information outside of the US HQ accounting dept.
Besides... JW.borg IS already in a tax paradise... The US, where religions are tax free...