I had 4 heavy tanks beside a wall, the other side, was a air defence. Rally the air defence.
Should take 2 sec for 4 heavy tanks to destroy the wall, then a sec or two to destroy the building.
Instead, they drive around a broken wall, around 1.5 lengths of building walls, to the other pointy end of a bastion. On a clear path, that alone takes longer than killing the wall they were beside, and killing the building. However, they drive over an already triggered max level barbed wire, now their journey takes easily 5 times longer, and troops on the other end of the screen are almost at location.
Troops destroy 2 bastions, troops arrived from North and South at similar times. The Southern bastion wasn't even protecting the air defence... It was just, "in the way". So instead of running around the bastion, it'll be quicker to blow it up and drive through the rubble....
Finally, nearly a minute passes, the air defence is destroyed. And by the time the battle time ends, the last 3 tanks finally escape the broken bastion, but first, they had to drive back n forth over the rubble to make sure it was well n truly crushed.