No, they are completely and accurately adjusted.
In 2013, the cap was 123mill, now it is 167 mill. That is an increase of 35.7%.
So if we use the mid point of 5-6 million, or 5.5 million, that would be the equivalent of $4,053,000 in 2013 dollars.
In 2013, the Patriots had 5 players on the roster making that much. Your argument adds up to saying the 3rd safety, playing under 50% of the snaps should be paid in the vicinity of the top 5 players on the team.
I would imagine a guy playing 50% of the snaps probably comes in anywhere from 20th to 30th in importance to the team, and based on 2013 those players cap numbers were 1.015 mill and 683 k, which in 2017 dollars would be 1.377 mil and 927 k, so no, the numbers do not back up your claim.