I highly doubt Ottawa takes Kotkaniemi (they may even make a similar deal with Detroit in which case we lose out on JK), so I threw Tkachuk's name there. Replace him with any other player if you wish. The most likely scenario is we take Kotkaniemi but ideally we make it so Zadina goes west.
If you got to 5 and somehow both Zadina and JK were gone, then grab Hughes or Boqvist. A top pairing PMD is just a gaping a hole as C, albeit one actively created by our stellar management team who seemed hell bent on creating a D corps of Weber and five Jordie Benns.
My guess is that if Arizona jumped up to take Zadina, then Ottawa would take a D or possibly Tkachuk, and Montreal would get JK anyway. But if Ottawa took JK, then taking a PMD at 5 fits the team's long term needs.
Alternative is to float the idea with Arizona, then go to Ottawa and tell them if they want Zadina, then they have to trade up from 4 to 3, and prevent Arizona or Detroit from doing so. Make the plus the Sens' 2019 2nd RD pick and get something for the honor of not selecting the consensus #3.