Source: the only reason for making this man the brother of Wilson and George Gordon is that in the TAB, he and George pay exactly the same tithes and are living side by side on Plots 7 and 8, suggesting brothers who have shared the father's farm. They also must be roughly the same age as they have children baptised on the same day in 1st Kilrea. However, there are two Williams in the 1931 Census, one called Wiiliam Snr and this one called William Jnr - if this is Jnr, then his father was called William not Thomas and he is NOT a brother of George and Wilson.
If he IS the man in the TAB, then he is also in the 1831 Census living in Houses 37 and 38 in a household of 3 males and 3 females - but, he is a little too young.
BB: William and Elizabeth married abt 1824 - children are Catherine Gordon (born May 16, 1825 - 1st Kilrea Bap), James - 1826; William John Gordon (born Jan 12, 1840), Thomas Gordon (born May 17, 1842); Hugh Stewart Gordon (born July 13, 1845)