From the last thread :
Benning literally said exactly this at the time of the trade. Said that during the contract negotiations with Dorsett, Dorsett said he wanted help in the fighting department and Benning promised to give it to him.
Your logic leaps like a frog on a hot stove.
Just because Benning wanted to add another willing combatant to the roster doesn't mean he decided to make Prust for Kassian happen no matter what. You can't just ignore how long Kassian was rumoured to have been shopped. This doesn't equate to Benning holding out for Prust because Prust was their target.
You also can't ignore how complicated addiction treatment is. That's the most important element in all this, and one that is being reduced to irrelevant in this discussion. Seen it posted numerous times that Benning "should have just checked him into rehab." As if it was just that easy. One key to overcoming addiction is changing habits. How many times have you heard a smoker trying to quit saying "it's hardest after a meal or with my morning coffee." This speaks to the habit side of addiction, not just the physical side.
Montreal was willing to take a chance on Kassian, and Prust filled an identified need. Thus the deal got done. Doesn't mean Benning wouldn't have taken a different return for Kassian, but there's been zero rumours I've seen of other deals being available. And clearing waivers shows just how low Kassians league wide appeal is. Everything about this deal says moving Kassian was the priority, the return was secondary. Prust happened to kill 2 birds with one stone as he was the type of player they were looking to add, and it allowed them to move Kassian. No evidence to suggest they were targeting Prust over other offered deals though.
As bad as Prust is, he had a stretch of games where you could see the player he used to be. There was some potential being on a new team and in a contract year would squeeze a decent season out of Prust. Obviously didn't happen, but there weren't any other deals for Kassian (that we know about) on the table, and Kassian needed a change of scenery. Didn't work out for us, but if it does for Zack, then it was worth it imo.