Greetings,
While in the real world tanks can shove over trees, there are limits. Everytime you decide to hit a tree on purpose there are a few things that can happen:
You knock the tree over.
You knock the tree over and mess up the fenders and get yelled at by the PSG
You knock the tree over and get the track caught on the stump and throw a track (not fun, lots of lifting of heavy stuff becomes involved)
You hit the tree and find out it was a bit to big / to well rooted to knock over - which stops the tank dead in its tracks (pun intended!) and throws the people in the turret violently forward. Normally there are many choice words directed at the driver following such an event.
When you drive into a building there are things that happen also:
You drive through and find a covered and concealed position from which to fight
You drive through, the roof/wall falls and knocks the maingun out of boresight. So, now you get to rezero/boresight the tank under battle field conditions.
You drive through the wall with the maingun pointed forward and push the maingun out of battery
You drive through the wall to find out the house has a basement - you have entered a turret down position with no way out until the bulldozer or recovery vehicle arrives....not to mention the sudden downard movement and impact on crew members.
Most TC are very unhappy with a driver who consistently runs over trees as it is only a matter of time until something bad happens.
Regards,