There are no Thomas Cleators ch exactly in 1816.
There are 2 in 1814:
Thomas ch 09 OCT 1814 Jurby s/o Wm Cleator and Elizabeth Stephen
Thomas ch 24 OCT 1814 Andreas s/o Wm Cleator and Mary Radcliffe
There are 2 in 1815:
Thomas ch 30 APR 1815 Lezayre can be eliminated as he died on IOM and was outlived by his wife Margaret Jane.
Thomas ch 30 APR 1815 Lezayre s/o Thomas Cleator & Mary Corlett

The next are not ch until 1819

How did you come by the 1816 bd for Thomas?

Given the age difference, he might have been married before?

The 1841 IOM census index has 3 possible Thomases:
Thomas 25 Braddan 2 5 19 s/o Thomas Cleator & Mary Corlett--Eliminated
Thomas 25 Lezayre 3 9 39 s/o Philip Cleator & Jane Quayle--Eliminate md Ann Killey
Leaves
Thomas 22 Maughold 1 6 20 s/o Thomas Cleator & Jane Taggart ch 1811

The marriage certificate might have fathers for each the bride and groom.