You do not get Tanguay for that exchange. Train's left the station on that kid's availability; he is maturing into a bonfide star. Besides Avs add salary (in pending RFA Hamrlik) and give up a solid prospect in Boychuk. And their current D corp is not a weakness. Tanguay will be up soon for a huge increase in $alary, further making it a non-starter for NYI.
I really don't see Calgary's incentive to move the recently acquired Warrener, though they could certainly use Parrish. For NYI, any move of Parrish is likely going to have to result in more than a $500,000 reduction in payroll, which is the relatively small difference between MP's and RW's respective salaries.