Well, I'd be very careful. I'd wager there are twenty times as many people doing ancient political philosophy in phliosophy departments. You may like political scientists better than philosophers, but the philosophers like you much better than the political scientists. And as for your pragmatic reason, philosophy departments are going to be just as impressed with a publication. More generally, I would argue that you are proceeding in about as unpragmatic a fashion as possible. How many people can you name who do ancient political theory in political science departments? Getting into a great program is great, but the job market is no joke. And just because you write a great thesis on Aristotle at say the Princeton politics department and have somebody from classics on your committee writing a letter for you, there is no guarantee that you will get a good job. When you go on the market, you will find that most political science departments are not looking for a theory person. The few that are looking for a theory person probably won't want an ancient theory person. The few that are open to such a person will be swamped with applicants because political science theory is a super tough market. Nobody in classics is going to want you because you come from outer space. Perhaps a philosophy department with a desparate need of someone to teach Greek philosophy will look favorably on you, but it will likely be lesser school and you will be back in philosophy anyway. You will be an oddball and oddballs are a problem. Academia has been professionalized and oddballs are not welcome. I repeat, there is nothing pragmatic in the way you are approaching this. Indeed, it is unpragmatic in more ways than one.