Does the sentence have a grammar problem?

[Floratang]

Since the list came mostly from ancient Greek writings, though, only sites that would have been known to the ancient Greeks were included.

[Canadian45]

It sure does!
1...Omit "though,".
2...I would replace "would have been" with were. There is no good reason to use the wordy perfect tense when simple past tense is very correct and fits better with the rest of the sentence. Though ''would have been'' is not grammatically wrong, it seems out of place here.

[Yankee]

I disagree.

There is no grammar problem. The only thing one might be able to argue about is style.

The sentence begins with 'since', so it is giving a reason or justification for something. I assume the word 'though' was inserted to indicate a contrast with a previous statement. If you remove the word 'though', you begin to remove the reason for using 'would have been'. Grammatically, there is nothing wrong with using either 'though' or 'would have been' in the sentence.

Since we don't know the rest of the context (sentences before this one), it's really not possible to judge whether the use of 'were' would have been better in the sentence.

As a "stand-alone" sentence with no further context, the omission of 'though' and the use of 'were' instead of 'would have been' is fine. However, sentences normally occur in larger contexts and that affects the choice of words, tenses, etc.

Amy

[Canadian45]

Hi Amy
There may well be some missing context but I took it as a stand-alone sentence. Maybe I had my blinkers on. However, I am not sure that my preference for were would change.

[Alan]

Hi floratang,

Your sentence

[Yankee]

.
Well put, Alan.
.