Excellent idea....
In 1851 Thos Hollingsworth was a music teacher, aged 23 from Hants (census)
In 1881 Thos Hollingworth is an actor , aged 54 from Hants (census)
The assumed DOB's match, and music teacher to actor is a reasonable match.
He gets married in 1852 to Isabella and they have 3 girls, prior to Isabella dying (we are sure confident that's her?) in late 1866.
there's no record of them in the 1871 census???
He then appears again in Durham in 1881 census with another son Thomas Richey born 1866-1868, potentially as the result of a relationship after Isabellas death.
It is feasible to me, absolutely.
Additionally, Thomas Richey lists Robert Richey as his father in 1914, well...
Thomas 'Robert' Hollingsworth.
Perhaps Thomas went by the name Robert thru preference and simply added the stage name Richey.
Thomas Richeys oldest son (my Grandmothers brother) was born in 1915 and named ROBERT RICHEY also!
If as seems very possible Isabella dies in Holborn late 1866, perhaps in childbirth with Thomas Richey.
Perhaps Thomas Hollingsworth ran off & left Isabella with the (girls) children, and she then had a relationship with Robert Richey which produced her son Thomas Richey.
There's no suitable birth registration at the right time/place to suggest that Isabella died as a result of giving birth to a live-born child.
Have you considered the possibility that Thomas HOLLINGWORTH (an actor in 1881) and Robert RICHEY are one and the same person - the latter possibly being a stage name for the former? Bear in mind that Thomas had a middle initial R in 1851 and a middle name Robert upon the baptism of two of his daughters (see above).
Since Thomas is "married" in the 1881 census, Thomas RICHEY the son might be a product of a relationship entered into by Thomas HOLLINGSWORTH after Isabella's death. He'd still be a half-brother to Catherine, Helen etc.