I'm not saying that AC has anything to do with the seniority list but I think the triumphalist attitude of the AC unions/locals re: merging the seniority list is going to make the CP locals/unions less likely to honour picket lines for a strike initiated by the "original" AC employees. I know I'd be tempted to stick it to the AC people if I were a CP employee.

CP's pilots may have not wanted to "scab" the AC routes during the last AC strike but things might well be different if the CP pilots are put at the bottom of the seniority list.