I think the Caps pass on this, unless freeing up the ~2M is necessary for another move, which seems unlikely given the guys reportedly available. As disappointing as this past year was, the ceiling with Mantha is still higher than Armia's, and it's an expiring deal.

But you could buy him out for only 33k this year, saving you 5,667 millions…

Armia's Buyout this year is like 50k or something
Then 1m next year ,1.5 mill the year after and 1m the last year.
5.6m in space for nothing but 3.54m cap hit over 4 years

There's still some good talent out there you could get with that cap

Caps pass on this

Hoffman makes more sense. Armia is a worse player than mantha and has additional term on his bad contract. Makes no sense for the caps to make this trade unless Montreal adds a pick