>>715388262More like 5 out of 9 minimum and 8 out of 9 in ideal circumstances
Demo, Spy and Soldier are all obvious
Sniper can outrange it if the engie builds it in a bad spot, can kill the engie, and can deal massive burst damage with a charged shot or arrow
Medic can ubercharge letting whoever's with him kill it
Heavy can out-trade it if the engie isn't there, especially if he has a chance to pull back for a sandvich. He can kill it in half a second if revved and point-blank, and can easily outdamage an engie healing it if he has an uber
Scout can run faster than it turns at point blank so if you can get that close its dead
Pyro can airblast rockets and his homewrecker oneshots minisentry and twoshots everything else (if you can get that close)
Only engie really lacks a way to deal with another sentry