Armor balance on breakthrough is utterly broken
Whoever is in charge of balancing Breakthrough clearly did a terrible job, even playing a single round makes it obvious how extremely poorly balanaced putting any armor, let alone the overwhelming amount for some maps in that mode is.
First off, it's bad enough that the amount of armor so heavily favours attackers - Mirac Vallery for instances sees points in the map where attacker have 2 tanks to defenders 0, or 4 tanks/IFV to defenders 1.
All of this is made egregiously worse by the fact the nature of the game mode makes it impossible to flank and destroy enemy armor. Tanks can, and often do, sit back in enemy OOB area endlessly spamming the objectives where they know they're next to invicible because no enemy can reach them, and a single engineer can out-repair just about any damage that's thrown at them.
Maybe, just maybe you'll be lucky enough to be on a team with enough engineers to take out a tank, but I can say testify from 80 hours of breakthrough that's very rarely the case. And, even if you are that lucky, taking out one of the tanks is never enough, you'll have to somehow coordinate enough to take out the rest... and repeatedly as they respawn.
Get rid of the armor on breakthrough, or at least make it so that they'll never respawn and they can't cheese the entire match.