Everything with a projectile can shoot through hedges.
I was wrong i really thought the AVRE couldn't shoot through hedges.
I also tested how many shoot you need to kill an Elephant, the AVRE needed 5 direct hits and take easily 2 hits from the Elephant onward and one hit backwards. With support the AVRE will get crushed.
The AVRE got pretty well adjusted in the last Balance patch. He is now in a good spot and unlike the ST it cant shoo through sight blocker so you cant be surprised by a rocket bomb.
It can be countered by dodging with micro and flank attacks when the AVRE is on reload.
I had a nice game vs. PanzergrenadierAngreifen where i used Commandos with Brens.
I give them maximum one Brengun just to wipe these 5% hp squads who otherwise will survive by retreating after an ambush.