HI .. yeah I'd originally just copied it off Ancestry - it appears they were known by both names .. see http://www.oxforddnb.com/view/10.1093/ref:odnb/9780198614128.001.0001/odnb-9780198614128-e-27704 . If you look at my page for him I have a note for this, but indeed the "William Steuart" name might have been more common.
I have collected many 'loose ends', together with more recently published information, in a biographical article 'John Townsend Trench (1834-1909)' in the Brethren Historical Review 16 (2020) 42-51. 'Towny', as he was often called, was a pretty colourful character! Timothy Stunt