I disagree with your characterization. It is akin to “Lutheranism was just a movement within Catholicism. It is expendable;I think Luther would agree.”
Methodism may not have started out in England to be a whole new denomination, but one of the most important features of its founding so close on the heels of the American Revolution was Wesley sent Bishop Francis Asbury here, and Methodist Episcopalianism thrived rapidly in the new United States. Methodism’s practice of circuit-riding pastors helped spread the gospel and plant churches all over a frontier nation. In the 19th and early 20th centuries it was one of the largest social organizations in the U.S., with hospitals, retirement homes, universities and charities such as Good Will. Unfortuately, Methodist Episcopalianism was infiltrated by Liberation Theology and communism starting in the 1920s via its returning missionaries from South America and Africa. The merger with the Evangelical United Brethren Church into the UMC and the Youth Rebellion of the 1960s ravaged the liturgy and the seminaries. The UMC has since been progressively destroyed as a Christian church. But its history was powerfully intertwined with the founding of our Constitutional Republic (”if we can keep it”).
I don’t disagree with any of your excellent exposition of history, but even John Wesley claimed his Episcopalian identity on his death bed, if I remember right.