The issue the PA had (has) with adding two additional DIs for two less Canadian backups is it would swing the PAs voting majority to imports. Currently, teams are required to dress a minimum of 21 Nationals, minimum of one Global and maximum of 20 American players. Simple math then, you are proposing a gameday roster of 19+ nationals, one+ global and a maximum of 22 American players. Add that up across the league and you have Americans being able to form a majority pretty easily. Obviously, the Canadian players who enjoy the current voting balance don't like that.
The big question is why they ever included the ratio as part of the bargaining in the first place. You can't take it back now but in essence it's simply a league rule. The players can't bargain their way to other rule changes like the length of games, the definition of pass interference, etc.
Note: In my previous post I omitted the word NOT before the word correct. That was the opposite of what I meant to suggest.
I explained the math and yours is not correct. There are more imports than Canadians already. Only the Lions have 2 Canadian QB's but still have 21 imports and 2 globals and 22 Canadians. Globals are part of the CFLPA as well.
I also suggested replacing globals with 2 import DI's in an alternative choice. That's a net zero change to the Canadian content.
Why the ratio exists is a hard fought priority for some fans. While I disagree, that's their view.
I'd reduce the number of Canadian starters to 6 from 7 but that will anger a bunch of CFL fans.
The smaller argument will be a new balance of the non starting players like the DI's.