You want to know how many columns are match for each row? For example, 2 out of 3 columns match=> 66.7%, 1 out of 3 columns match=>33.3%, correct?
If so, you can transpose table and compare them by JOIN and identify difference by formula tool...so on. Please see attached workflow.
By the way, I suppose you create unique column by concat first three column, however, I recommend to put a separator like semi-colon ; vertical bar| etc..
For example, if there is another record like:
Customer Name: John, Customer ID: 11, Number of purchases: 0
Then, concat value would be John110, which is identical to first record, and not a unique one! By using separator, they look like;
John;1;10
John;11;0
These values become unique.
