Question on pronouns

[Harry Spier]

Dear list members,

On page 49 of Coulson's Teach Yourself Sanskrit he says:

but then he says on page 63

I'm unclear why he says etat tat citram is wrong (subject can't go first)  but

eṣaḥ saḥ brāhmaṇaḥ is ok.

Aren't the sentences the same form except the first is a neuter noun and the second is a masculine noun.

Thanks,

Harry Spier