Hearns in Bermondsey c 1814

[wilcoxon]

I am really struggling with this puzzle and just hope that someone might be able to check Prs. I have this 1841 census.

1841 St Mary Magdalen Bermondsey   HO107 /1048/ 4
Mill Street Bardonie Buildings
Thomas Hearn 25  b 1814/15  Waterman
Sarah Hearn    25      b 1815?
Edward Hearn 14 b 1827   
Thomas Hearn   4 b 1837   

And these IGI records.   
IGI Edward Percy  s/o Thomas and Mary b 1827 St Mary Magdalane Bermondsey
IGI Thomas s/o Thomas and Sarah. b 1837 St Mary Magdalane Bermondsey
Edward Percy is the man I`m following , many more generations have Percy /Percival a a middle name.
There is no indication to relationships in 1841 and it looks as if Edward is not the son of Thomas , even if he married twice.

1851 2 Gilberts Court Bermondsey Southwark.  HO107; Piece: 1560; Folio: 415; Page: 16;
Thomas Hearn 37 b 1814 Waterman b Surrey
Sarah Hearn     36 b 1815      B Surrey   
Martha Simmonds  81 wid  Mother in Law. Formerly School mistress. b Berks

In 1851 I can`t find Edward b 1827 or Thomas b 1837, but in 1861 Edward turns up again.
1861
Edward Hearn 34  b 1827 High man  b Bermondsey Surrey
Jane                  28                b Bermondsey       
Thomas E             7           b Limehouse  Middlesex
George W             4         b Lime house
Frederick P           2           b St Johns  Surrey
Alfred                  3 Mths   b St Johns
Sarah Ware         72  Mother in law. Retired governess b Lincoln

Later 1891 census gives Edward with his P middle name b 1827

So . after all that I`m trying to find the relationships of the Hearns in 1841,  how is Edward related to Thomas.
Is the answer in the Prs 

Thanks for looking at this , and hope you can help.

[Frances]

There is this entry

Thomas Hearn Born 28 February 1812 Baptised 29 April 1812 St Mary Magdalen  Parents Thomas and Mary

Frances

[wilcoxon]

So , I wonder if Thomas b 1812 and Edward Percy b 1827 could have been brothers ?
I wonder where the Percy connection came into it, after Edward Percy, 1827 there was his son Frederick Percival Hearn b 1859, his son Percival Arthur Hearn  b 1896 - - 1952  and  his son   Edward Percival Hearn .