Umm maybe review guidance on sales concessions again. And double check your data. You know, contact a party to the transaction like one of the realtors. I think if someone decided to review your work, "They all offer a percentage of the sales price." is not going to cut it. And "you only adjust what is typical". Be ready to have the source of this information available, cause that isn't necessarily true.
Are referring to residential appraisals? Cause if you are here is the key verbiage from FNMA "The need to make negative dollar adjustments for sales or financing concessions and the amount of the adjustments to the comparable sales is not based on how typical the concessions might be for a segment of the market area. "
https://selling-guide.fanniemae.com/sel/b4-1.3-09/adjustments-comparable-sales
If you are using a F/F form, part of your SOW is to follow their guidelines.