Those who want to insist the Trumpets and Bowls are the same events from different angels, make a strong argument when they point out certain parallels between the 2nd, 3rd 5th, 6th and 7th of each.
Well they have no parallel for the 1st, they're not the same at all. And the 4th is the opposite effect. For 2 and 3 it's clear the Trumpets are only partial while the Bowls are complete. And for 5 and 6, the parallels are small superficial details of larger complex situations.
To a certain extend I don't think these parallels are coincidences. As I said before Trumpets are warnings, I think each Trumpet is a warning of each Bowl. And the Seven Angles may well be the same Angels connected to each. This is a conjecture, but I think maybe each Trumpet is 42 months before each Bowl.