Zero / Ten was always the likely option when the Isle of Man adopted it to replace what were their "exempt tax" companies. Any greater tax on those companies, and they would have migrated to the IOM, so naturally Jersey and Guernsey followed suit.
Exempt tax companies were not just within places like Jersey - Luxembourg had "holding companies" which did much the same. Luxembourg had to abolish those, but sought its own work-a-round:
The replacement for the 1929 holding company is the Family Private Assets Management Company, or SPF. These new vehicles are prohibited from commercial activity, and are limited to private wealth management activity, for example the holding of financial instruments such as shares, bonds and other debt instruments, in addition to cash and other types of bankable asset. The new vehicle is designed to be exempt from corporate income tax, municipal business tax and net-worth tax, and from withholding tax on distributions.
In the meantime, no one has given any thought to any replacement to this, although Guernsey are being more pro-active, and are suggesting a 10% corporation tax. But perhaps they should look in part at least to the Luxembourg model, as this has not attracted the same level of criticism from the EU Code of Conduct.