Lets compare some defensive and two way stats from 2019-20, with the team rank since these stats are almost irrelevant otherwise, since they are heavily influenced by team puck possession.
Relative CF%
Hughes 6.0, team rank 4
Dahlin 3.6, team rank 4
Makar 2.6, team rank 7
Heiskanen 2.5, team rank 10
Relative FF%
Dahlin 1.5, team rank 8
Makar 2.5, team rank 10
Heiskanen 2.0, team rank 10
Hughes 5.5, team rank 5
Blocks : Heiskanen 84, Dahlin 51, Hughes 46, Makar 47.
Hits: Heiskanen 40, Dahlin 72, Makar 45, Hughes 7
Takeaways/giveaways: Heiskanen - 37, Dahlin - 26, Hughes - 25, Makar -6.
What picture does these stats paint? There is not much to separate them defensively, based on this. Makar is probably slightly worse than the rest in his own zone, but defensive ability is generally not really something you can base on stats, I must admit. Offensively though, there clearly is a substantial difference. Heiskanen has not been able to produce at nearly the same rate as the others outside of one playoff run.