Need to check on Alfred. Are the two Harriets not different ladies? Is Alfred not the child of a different Harriet Baker?
Harriet Lane, born Market Lavington 1854 does not have a child Alfred with her in 1881 in the workhouse.
In the same year, Harriet Baker born Little Cheverell 1841 with husband George born 1845 West Lavington does have an Alfred born 1879 West Lavington all living Market Lavington, Alfred is in Swindon in 1911.
In 1891 I find only the second family, still in West Lavington and presumably the Alfred with them age 12 is the one with them in 1881 when Harriet Lane was in the workhouse. I see the Baker/Lane marriage in 1884 but so far find no later info. However, if he is not Harriet Lane's child, then he is irrelevant to your history?
maxD
Later - I would go along with William being in Newport in 1891. He is in the same parish of Woolos as George who is with (presumably) uncle William C Lane. The latter is in West Lavington in 1871 with a sister Harriet. The Jun 1895 West Derby marriage of William Alfred Lane and Mira Smith looks like your man so his move from Newport to the Liverpool area was 1891-1895. His trade in 1901 was carter so perhaps he took up the trade in Newport, travelled to Liverpool, met Miss Smith and the rest is history (conjecture creeping in!).