Contacts with multiple phone numbers - text going to wrong number

I found a previous answer to a question about 2 people in one contact (say husband/wife) with 2 or more phone number in the same contact, but text messages going to wrong number:

Welcome to Apple Support Communities! It sounds like you have 2 people saved on one contact card and they are receiving each others messages. I'm happy to assist you with this.

The Contacts app is designed for each contact to have their own contact card unless they share the same phone number. This helps avoid any confusion and crossing of contacts and phone numbers. If you prefer to continue using your contacts the way you have been, you can try deleting any previous message threads you've sent to this couple. Next send a new test message to each one and make sure you select the correct phone number for each individual prior to sending the message to see if it works. If the messages continue to cross, try creating separate contact cards for each one of them:

This does not resolve problems where a person has several numbers - separate personal cell and business cell - and the text going to wrong cell. I have numerous contacts with multiple cells - business and family contacts. I do not want to create hundreds of extra contacts. Seems like this should be an easy fix.