Lake Peipus wasn't against pagans, it was against Novgorod. Also there were like only 40 Knights actually there (it was a force marshaled by the local Bishop) and it was outnumbered 3-1, with most of it's forces composed of native levys of doubtful quality, all fighting on the ice. I would hope in those circumstances, Novgorod's greatest hero could pull off a victory...
And I reenact the 14th century, you just see how taking Teutonic land works out for you
Sir William, the Grosskomtur (Grand commander) was the 2nd highest rank in the Teutonic Order, directly below that of Hochmiester.
Also how dare you accuse me of chocolate milk thievery! This is outrage!