As non-spouses cannot benefit from the exemption available for spouses, it is likely that only dividend sharing with a commercial basis will be acceptable to HMRC.
Where the arrangement with your second shareholder has a commercial basis this will support dividends being taxed separately. Your second shareholder does not need to be able to carry on your profession to be of commercial benefit to the business. They can provide assistance with administration, financial management or funding.
The efforts of the non fee-earning shareholder should be documented clearly to emphasise the commercial basis of the arrangement.