The Mennonites baptized by pouring, then .
That is false and there is evidence to show he did not baptize by pouring but by immersion. The modern movement does pour.
What evidence? Menno Simons on two occasions rediculed the baptism by Catholics as a "handful of water." Luther responded to that charge of a mere "handful of water" saying:
"In the second place, here is also the overthrow of the assertions of the Anabaptists and such like company. Who thus teach...the beloved baptism to despise, as to be nothing more than plain common water, from hence they indulge to slander it: 'What can a handful of water help the soul.'"
Menno Simons commenting on 1 Corithinians 12:13 said:
"Moses believed the word of the Lord, and errected a serpent: Israel looked upon it and was healed, not through tghe virtue of the image, but through the power of the divine word, received by them through faith. In the same manner salvation is ascribed in scriptural baptism [doope] Mark 16:16, the forgiveness of sins, Acts 2:38; the putting on of Christ, Gal. 3:27, BEING DIPPED INTO [indoopinge] one body - 1 Cor. 12:13"
Take note that the words "DIPPED INTO" are a translation of the term "indoopinge" which is comes from the same root as the term translated "baptism" [doope].