Could Gaskin be John?

[Trees]

Please can anyone shed some light on this strange two part situation?
1. Elizabeth Mann married Robert Stevenson Ford 26 Feb 1883 in Chelsea she gave her father as John Mann a Carman
Harriet Mann married George Baker  26 Jul 1891 St Andrew, West Kensington, she gave her father as John Mann a Carman and the witnesses were R.S.Ford and E Ford
I conclude from this that Elizabeth and Harriett were sisters.
In 1891 Martha Mann is mother-in law to George Baker so from this I think John Mann was married to Marhta and they were the parents of the girls continuing the same lines in 1881 John 7 Martha are in Kensington and have a 20 year old daughter Hannah with them
Hannah born 1861,Elizabeth born 1864 Harriet born 1867 all born in Norfolk and marrying in London
But then here's the FIRST MYSTERY
1871 We find Martha with Hannah 11, Betsy 6 ,Harriet 5,and Blanch 3 all born Hardingham Norfolk in Chelsea BUT the head of the household is Gaskin not John.
The last three all have mother MEALE but I can not find Hannah's registration
In 1864 Gascoigne Mann married Martha Male in Hardingham
Hannah would be born before that marriage

Question 1 is is it possible that Gaskin was John?
Question 2 who weree Hannah's parents?

[Trees]

Part 2
Part two is another  Mystery
Gaskin was the son of Richard Mann and Hannah Hutson.....or was he?
Richard married Hannah Hutson in Garveston in 1817. Their first son was baptised Hutson  Mann  he was followed to Garveston font  by six siblings
BUT  Sarah who must have been born in 1837 and her brother Gaskin were baptised together on 7 Sep 1840 they are children of Richard and Hannah Mann and dad was a blacksmith then there is another entry for the baptism of GASKIN the bastard son of Hannah Hutson on 21 Feb1841 A Gaskin Mnn is regestered Sep qtr 1840  no mother's name given AND a Gaskin Hudson in Mar qtr 1841
How many Gaskins were there? Surely the child wasn't baptised twice it is not allowed by the church and why has Hannah reverted to her maiden nameRichard and Hannah went on to have a Henry/Harry in 1843
This has been easuer than I thought of course there were two Hannah Hutsons the singlr mother was born 1820daughter of Gaskin and Ann the other married Richard Mann in 1817.
That just leaves the first problem. did Gaskin get fed up of the name variants so adopted the name John?