Re-reading your original post, it seems to me you are getting hung up on the XY min/max of the data you are matching to; yes, in your second post you are correct in saying you have misinterpreted thier applicablity to your issue.
When you match to polygon features like a postal zone, your resulting geocoded point will be located on the polygon centroid. It does not matter how big that polygon is. I'm not a good enough mathematician to describe how to determine the level of precision, but in layman's terms I can understand, it's pretty low. Using my targets example, you are going hit the target over and over somewhere, with a very low probablity of being in the bullseye and more than likely on one of the outer most rings.Think about it; if one of your addresses is actually located on the centroid of the polygon, you'll be on the bullseye, right? But matchig 1,000 records against a 100 km-square polygon is a bet I wouldn't take. A component of precsion is also how often you repeat that bullseye shot.
As a hobby, I shoot rifles at long distance targets, hence my propensity of the target analogy. I can stack hits in the bullseye all day long at 200 meters. That's the range at which I 'sight' my scope, so shooting groups of 5 shots, I expect them to be within a couple centimeters of each other and in the the bullseye. My groups expand as range increase, and that's to be expected. However, if I'm at least hitting my target at 800 + meters one shot after another, it's a good day at the range! (The target on the right above, would be a thrill at 1,000 meters; trust me!)
The issue you are actually faced with is the level of comfort you take in using a geocoder ( or series of geocoders) in which you really have no knowlege of the quality of data that are used. It's a leap of faith at best; for what I do, I'm not comfortable with that leap. But you may be, and that's just fine!
In theory, point data will provide the most precise results, but you'd need to know how the point was derivied to be absolutely sure. If the point is 'just' the property parcel centroid, that's pretty good, but not as good as if the point was manually placed on a high resolution, well rectified image at the front door of every house.
Assuming the data you are using is of relative good quality, the precision of resulting geocdoded points in order of highest to least is points, lines and polygons for the matching data. How to quantify that level of precision is beyond my means.
The data you are actually matching plays a role in the results as well, but that will be at least another cup of coffee, perhaps two for me to discuss...
Hope this helps!
That should just about do it....