To give my two cents on the fourth line discussion.
Fourth line is usually considered to consist of players that are tough opposition to play against. They compete hard, and it's an advantage if they can be physical too. Ideally they're also defensively responsible. Key thing is that while they might lack in terms of scoring ability, they still need to boost up the mentality for their actual scoring lines to make sure they can put up results when it's needed.
I think WSH's and TB's fourth lines excel in this form of game. To the same extent where the Isles fourth line did in the bubble playoffs and 2021 ones too, they were praised for a reason.
You don't make a solid fourth line by putting the random players there that simply don't fit higher in the lineup. That's more just ditching the whole idea of the fourth line completely, and filling up the slots with players that are of different sort of expertise. I think
@Ducharmethedominator 's idea of putting Pitlick-Evans-Hoffman as the "fourth line" represents this idea far more than
@NovaSpartan 's shout of Sheary-Dowd-Hathaway does.
Personally, I would 100% choose the WSH's fourth line over MTL's "fourth line."