Celtic have a dedicated researcher and Scotland has a head researcher, as well as SI staff overseeing the research. Researchers watch a lot of football and it is disrespectful to suggest they don't.
Attributes like Finishing, Dribbling etc are just a part of the bigger picture. For instance, there's more to finishing than just Finishing alone. Attributes like Decisions, Composure, Balance and Technique will all play a part in finishing off a chance. It's the same for probably all of the other Technical Attributes.
Researchers are open to making changes if someone can show that a player's attributes aren't what it should be. Backing up claims with data is the best way to do so.
I don't watch Celtic and I don't know these players, but quickly looking into some of these players' data, James Forrest averages 0.75 tackles per match, so hyperbole like "I've never seen him make a tackle in his life" is completely wrong and won't help the discussion.
Abada has a dribble success rate of 33,3% (though he does attempt a lot more dribbles compare to the other 4 you mention) might indicate that his rating is correct. If anything it might indicate that some of the others' dribbling could be lowered. CCV attempted only 7 dribbles so far, but has a 100% success rate, FWIW. McGregor has a 59% success rate. You may have a case for Starfelt and Welsh as they don't seem to even attempt dribbling much, with 1 attempt and 0 attempts respectively. Still though, as I mentioned earlier, there are more attributes involved in successful dribbling than just the Dribbling attribute.
If you look at any attribute in isolation, it's easy to do a comparison and say this player should be better than the other. It's the mix of all the attributes that makes a player what he is. It's often recommended that you observe the player's performance in-game and whether that matches up with the real life version.
If you do have data issues where you feel attributes aren't correct and you can back up your claims, please raise it in the Scotland Premiership Data Issues section here: https://community.sigames.com/bugtracker/football-manager-2023-bugs-tracker/database-and-research/
It can then be considered for future updates.