User blog comment:B214/Volume 23 discussion blog/@comment-31.11.129.16-20170319160510/@comment-10330822-20170319222049

But how many pieces worth is Roygun, that's the question?

Bova is interchangable with Rook, he's not the set Rook. Logically, if you want to use both Roygun and Nakiri, assuming Roygun is worth more than 3-4 pieces, which she should be, it makes more sense to make her your Rook and have Bova as the 3 piece Pawn. That way, you can have the 5 you need to use Nakiri as a Pawn.