If someone not named McDavid was playing like he is, that players would be in every Hart post as top3 candidate. And often #1. This should be 3/4 horse race. It depends on what you value most in your voting.
1. If you are choosing most important player for your team (and making playoffs), it's Josi, Sheshterkin and McDavid.
2. If you are choosing best player, it's McDavid or Matthews, maybe Josi.
3. If you are choosing, most unique season it's Matthews, Josi or maybe Gaudreau.
For #1, teams wouldn't make playoffs without those players. Sheshterkin has most likely played too few games to win, but even with that amount of game his impact is huge.
I would most likely give my first and second vote for McDavid and Josi. Don't know, which one is #1. Matthews and Sheshterkin as #3 and #4, don't know order. And maybe Gaudreau #5. But I can easily understand any other order for top 4, but can't see any reason to drop any other than Shesterkin out from there.