The four angels showed up to John in Rev. 7 as holding the four winds. Yet- when the angel that seems to have the harm the trees plagues speaks-he refers to the four angels to whom it was given to hurt the earth and the sea. Then a bit later he added the harm as to the trees. Does this show that he had the plague of the first trumpet time and gave it to the four angels to bring forth -after the seven "we" angels were done seallng some people?

Rev. 7 refers to another angel ascending from the east.

John would not have put it that way, as he had no idea if in the future he might be shown another one.
John is revealing to us that he has seen this whole set of "we" angels as having ascended from the east. John has made Rev. into a puzzle, because he was told to by the seven thunders.

The trumpet plagues sound in Rev. 7. They are brought forth by the four standing on the four corners angels.
to hurt - the earth, sea, and the trees
These seven plagues were given to them by the seven angels that were first seen as "seven angels" in the get their plagues role of chapter 15.

Rev 7:1 leads to chapter 12, 13, 15 and back to Rev. 7:2.
Now having the earth, sea and trees plagues, the four angels can bring forth the time of the great tribulation.
They wouldn't have those plagues, until they were given them by the "we' angels (7) that John saw come from the east in chapter 15.