How about this (untested): 1. Create a layer of the parcel in question 2. Use SelectByLocation to create a second layer of the adjacent parcels (WITHIN A DISTANCE OF 0) 3. Join the first layer to the second using the owner's name as the join field 4. Select all the parcels where a join occurred
The Dissolve tool should help do this. Make Owner1 and Owner2 the case fields. Uncheck the Create Multi-Part Features option. Any partially shared boundary will allow a merge. Any Count/Frequency on the output that is greater than 1 will be an indicator that two or more parcels merged (although it is not definitive). (Null values may cause a problem with the dissolve, so you may have to calculate Null Owners to a whitespace character to get correct results).
You could then run a Spatial Join with the Many to One option or your parcels against all Dissolve shapes with a Count/Frequency that is greater than 1.
Run a Summary Statistics on the Spatial Join output to find FIDs of Dissolved polygons that have more than one Parcel FID associated with it. These are the set of parcels that meet your criteria.
You can use a relate from the Summary Statistics output to the Spatial Join output and then to your parcels to select the collapsed parcel set. A join of these outputs to the parcels would allow you to create a merge symbology based on the shared Spatial Join FIDs.
Dissolve, Spatial Join and Summary Statistics are available for all licenses.