My KJV records Romans 2:15 Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;)
Now this means nothing without knowing what the subject is and verse 16 nails the purpose of what is being said.
16 In the *day* (has NOT happened yet) when God shall judge the secrets of men by Jesus Christ according to my gospel.
Verse 11 is the subject "For there is NO respect of persons with God.
12 For as many as have sinned without the law shall also perish without law: and as many as have sinned in the law shall be judged by the law;
Verse 13(For not the hearers of the law are just before God, but the doers of the law shall be justified.
14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, these, having not the law, are a law unto themselves:
Then comes verse 15 Which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;)
Note verse 15 is part of the ( beginning in verse 13.
Your point is?
12 All who have sinned without the law will also perish without the law, and all who have sinned under the law will be judged by the law.
13 For it is not the hearers of the law who are righteous before God, but the doers of the law who will be justified. [!]
14 When Gentiles who have not the law do by nature what the law requires, they are a law unto themselves, even though they do not have the law.
15 They show that what the law requires is written on their hearts, while their conscience also bears witness and their conflicting thoughts accuse or perhaps excuse them
16 on that day when, according to my gospel, God judges the secrets of men by Christ Jesus.
I would say the "they" of verse 15 has as its antecedent the Gentiles of verse 14 who have not the law but do what the law requires.
Maybe I don't understand what you're saying.