I have looked high & low for 1881, I agree would be key to tie together. The only thing I can think is census may be damaged, unreadable, mistranscribed or under another name.
Family also maybe took a return trip to Ireland for whatever reason.....
Added - also think there is enough evidence to link family together via baptism/ BMD/ godparent/ witness/ shared census etc, plus memory of OP Aunt re Holland family.
Hopefully the certs will help OP further.