The easiest way to merge information about individuals is by having a common attribute that can be used to identify and then link information that shares a common feature – email address, phone number, social security number etc.
To limit how Google links data to your phone number go to https://myaccount.google.com/privacycheckup/3?continue=https%3A%2F%2Fmyaccount.google.com%2Fdata-and-personalization
In the ‘Help people connect with you’ section make sure these settings are turned off. If you want people to have a (slightly) harder task of finding you with your phone number you should also turn this setting off.