I would think that would get it done for sure.

It depends on whether or not tkachuk is willing to sign a long term contract

This deal is realistic, but it would be really stupid of Ottawa to do, Tkachuk brings a certain something that very few in the league do, yes Eichel is an unreal talent who plays C, but Tkachuk IMO would be worth keeping over dealing for Eichel...

Pending a deal with Brady, I like it.

100% and its probably why Ottawa eobt do it

I don't see as good deal for Buffalo. Tkachuk is good but not a game changer. But in some ways it makes sense for both teams. Until Eichel is cleared medically nothing gets done.
Pretty certain Tkachuk has no thought of signing long term for Ottawa or Buffalo, though he is under team control for four years.

Taking out the 2022 1st seems ideal with how good the draft is likely to be and how much BTkachuk alone carries an Eichel return (I'd say like 2/3 of it alone)

He just turned 22 he might well have another gear

Either way he'll mature also

Huge asset ✔

I wouldn't even trade Brady for Eichel 1 for 1. Although Eichel is the better player, Tkachuk is younger, has more heart and is the leader for the sens right now. Super rare to get those kinds of players.

I think the Sabres would do this happily - if Tkachuk was say locked in for 4-5 years for 8-9 mil

Great comments.
I am sort of surprised that only @Talking_Senators who would not do a one for one and @Radu47 who thinks the first in 2022 is too much objected.
Buffalo needs, RHD prospects, NHL RW and draft picks or other decent prospects.
Thomson would be Buffalo's top RHD prospect, his ceiling appears to a career in the NHL but not as a top RHD.
White would give Buffalo another option at center, could he play RW?
The draft pick would not be a top 10.
Tkachuk would be Buffalo's top LW, is young and probably has not reached his peak.
He does not fill one of the holes in the Buffalo future, as he is a LW.
As for the value, it is one of the best offers I have seen on this site.
If Tkachuk were a RW, it would be a perfect fit.
If I were Pierre Dorion, I would keep Tkachuk and make a different offer for Jack.
Maybe Connor Brown?
He is only signed for two years, and I would imagine most Sabre fans would object.
EDIT:
I just had a thought, maybe Buffalo could add Olofsson then Ottawa could add.