Yes. Even Southwest a so called low cost carrier seems to have a boarding system that works.
AC boarding with 5 zones/lines like at YVR for the YYZ widebody flights also works. I understand most gates do not have the space for 5 lines.
The current system does not work well though for the most part Z1 and Z2 seem to board together with the GA sometimes calling them together. AC GA also seem to be understandably very busy behind the counter. If they came out and moved Z2 behind the Z1 in line or eyeballed oversized bags before the boarding starts things may be smoother and it does not have to be confrontational or aggressive either - I see other airlines do this.
So the choices are :
1) have a system that is rigid and organized to the n'th degree that does not require any intervention i.e. 6 boarding lines. We obviously do not have this at AC currently.
2) Staff so you have the ability to manage the boarding process proactively. We do not have this either as we have 2-4 GA handling everything from seat assignments, gate checking bags, upgrades and the boarding process.
3) Fix the current system closer to point 1 above since the likelihood of increasing staff/costs is slim. Since there is not enough space for 6 lines at all gates, have a Zone 1, 2, 3 lines all separate. Change Zone 2 to 4 when Zone 2 has boarded. Change 3 to 5 when Zone 3 has boarded. There is absolutely no point in lining up if you are in Z4 or Z5. This would keep Z1 line open for Z1 to board anytime. It would also allow AC to board families with small children from the Z1 line AFTER Z2 has completed boarding. No clustering or chaos. No excuses from people saying they were in the right line like now (Z 1/2 or Z 3-5). Everything is self explanatory and the GA just check everyone in and execute.