why not: "we eat at twelve always"
That word order is wrong -- or at least very unusual -- for English.
As a native speaker of English "we eat at twelve always" is perfectly grammatical to me and should be accepted.
What is wrong with "we always eat at noon"?
We're going for most accurate translation here.
JÍME VŽDY V POLEDNE = WE ALWAYS EAT AT NOON