Not necessarily.
Something that should be factored in here is that the two witnesses, in Revelation 11:6, smite the earth with all plagues<4127> as often as they will. The seven angels, in Revelation 15:6, come out of the temple with the seven plagues<4127>.
It’s reasonable to think that the two witnesses request that the vials be poured out. In Revelation 11:6 it says they have power to shut heaven, that it rain not, which occurs in the days of their prophecy and Revelation 15:8 says no man was able to enter the temple (in heaven) till the seven plagues were fulfilled.
The two witnesses are able to smite the earth with the same plagues as the seven vials. If you place the two witnesses prior to the seven vials then you have possibly of the plagues occurring twice.
While I agree to a degree with your point involving the 2Ws smiting the earth with plagues, personally I see that explaining some of the trumpet judgments, not the vial judgments. Which could mean that the 1260 days allotted to them could have begun as far back as the time of the 1st trumpet, which means that this 1260 days spans 6 trumpets. I'm not dogmatic about that, that it spans 6 trumpets. I just see it as being a possibility.
Assuming I'm correct, the 6th seal is only involving the 7th trumpet as far as I can tell, and that it indicates that the day of His wrath has come. And by comparing to Matthew 24, we see in verse 29, pertaining to the 6th seal in Revelation 6, that this is after the trib of those days, which also places His wrath after the trib of those days.
Matthew 24:29 Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken:
Obviously, immediately after is not meaning prior to something nor during something, it is meaning after something.
Immediately after his shift at work ends tonight he will then get in his car and drive to Walmart to get some groceries. No one would take that to mean that he will then get in his car and drive to Walmart to get some groceries, before his shift that night even begins, or during that shift before it ends.
Revelation 6:12 And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood;
13 And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind.
14 And the heaven departed as a scroll when it is rolled together; and every mountain and island were moved out of their places.
15 And the kings of the earth, and the great men, and the rich men, and the chief captains, and the mighty men, and every bondman, and every free man, hid themselves in the dens and in the rocks of the mountains;
16 And said to the mountains and rocks, Fall on us, and hide us from the face of him that sitteth on the throne, and from the wrath of the Lamb:
17 For the great day of his wrath is come; and who shall be able to stand?
And regardless what it might look like, stars of heaven falling to the earth, both accounts record this, and they both record that the sun goes dark. And that the latter records that the great day of his wrath is come. If it doesn't come until after the trib of those days according to Matthew 24:29, how could it have already come prior to the events involving the 6th seal? Which would incorrectly place the day of His wrath during the trib of those days. That is not what Matthew 24 and Revelation 6 record. That is contradicting what they record, and not, agreeing with what they record.
