The sealed book that is opened by the Lamb doesn't contain the trumpets or the vials in it.
The scroll (with seven seals) contains ALL events. Teh 7 trumpets and 7 bowls are part of the scroll.
The vial plagues were laid out in the book that John ate.
The symbolic meaning behind the eating of the little book is that it is a bitter/ sweet ending. All in all, devastation and death but eternal salvation and peace afterwards.
The trumpets were the time of a vision section revealed to John between the end of the 6th and the start of the 7th seal.
Vantage points, events overlap and accumulate. Action starts with 1st trumpet. Again the 7 Seals represents actions that take place in the trumps and the bowls.
Rev. 7:1 begins as to "And after these things I saw four angels..."
Just a vision!
What if after the 7th seal is opened and the time of silence, John just wants to be sure we know which set of angels have shown up?
John wants to be sure we know... ? This is the revelation of Jesus Christ. The same angels in Rev.6:12 do not take action til Rev.9:14 (to support and demonstrate my interpretation take a close look)
The Bible shows that the 1st woe (5th trumpet) ends before the 2nd woe can begin
I'm sorry but this angel releases the demonic horde from the bottomless pit, a crack in the earth (super volcanic eruption) releasing smoke that covers one third of the earth and you think these events aren't accumlative? So the smoke goes away first before anything else happens?
The Lord returns at the 7th trumpet sound while there is dark smoke that covers 1/3 of the sun, moon and stars. Granted the demon-like locusts torture for 5 months but death, fire, destruction is accumulative.