Too Long; Didn't Read
The conflict of top star developers is almost inevitable if you have several top people with identical specialization in one team. The worst thing is they all are probably right. Since you are a manager and not the top star developer you are not able to recognize which solution is better from the technical point of view. The best is to allocate the top stars on the project or at least on the parts of the project that are as far as possible from each other. The solution that worked particularly well for me was that I called the stars of the teams separately in advance of the conference call.