Farmers? phhftt..a tractor would make a great mess of those holed up in there if you were to put it in gear, point it in the right direction and jump free.

Greek farmer protesters brutally attack police

That wasn't brutal. We just got used to be trampled by the police.

What exactly are they protesting?

Does everyone in Greece get a womping stick?

If you're going to attack a mass of koopa troopers try a different strategy (the one they will use on you.) Target an individual officer. Get a large group of strong men, ~20. Grab a single officer and drag them away from the group. Begin beat down. This will immediately scatter the rest of the police officers. Have 2nd group of ~30 strong men then reposition themselves where the officers just were. Then surround the group and begin mass beat down. Remove helmets, shields, shoes, remove anything you can grab.

Also moltovs will open up an entrance really quick.