RAS is an objective score. You can trust it as a set of data points that have value in the scouting process.
McDermott knows what he wants in his CBs, so I'm sure a low RAS isn't a huge deal to them.
Where I'd like to see them give more weight to the RAS is RB. They can get super athletic guys in the later rothen. If they're a dime a dozen, then get the most bang for your buck.