For one, I trust Elections Canada to administer elections. More to the point, in my election, during the first couple of days of the campaign, my phones rang off the hook with people who wanted to be named to work at Elections Canada. I had never heard of any of them before and I have never heard from any of them since, and I suspect that these people called all the different parties so they would show up on all the different lists. If you have to say that only 50% are named by each party, they might have people who were named by all three parties, and everyone's named by everybody, so they could be anywhere.
I see that being problematic in implementation. I don't see any need for this amendment.