We get a lot of questions like this:
Did you think that Appraisers are stupid, or that they are out to get you?
Appraisers are tested and licensed and have to answer to a higher authority.
No matter what house you are comparing to; there will always be some features, some statistic that is different from the Comp houses; the square footage, the age, the condition, the upgrades, something.
The Appraisal takes these differences into account; it either credits the primary house or debits the comp house, or vise versa. When the figures and allowances are all added together, the numbers make the houses COMPARABLE.
If you think you can do a better job; I suggest you take the courses, study your toke off, and then serve the apprenticeship to become your own Appraiser.