Perhaps with getting criticals instantly, but they're a challenge to be and it's especially a challenge when you're facing a good sniper in battle while still juggling defending against other enemies.
Try facing against a good demoman or soldier who sticky bomb/rocket jump to get to the (for example) battlements on 2fort. Oh man, it's even crazier when the demoman knows how to stickybomb across the entire outside area in 2fort and rain hell on you from above.







