You have stated the Rev. 7 martyrs are saints who die after the Seal judgments. Have you ever tried to figure out how the four horses line up chapter-wise with the whole book of Revelation? Or does it overlap too much to do that?
I think the judgments in the Book of Revelation occur in chronological order. The seal judgments are first, followed by the trumpet judgments, and then the bowl judgments. In my opinion people who try to interpret the book in any other way wind up causing a lot of unnecessary confusion about what it says. The Revelation was written to help us understand the end times, not confuse us about them. I think the warning against adding to or subtracting from the book (Rev. 22:18-19) applies to interpreting it differently from the way it was originally given.