I disagree. The Great Tribulation is about the struggle of the Church against the power of the AntiChrist, and is based on persecution. The wrath of the Lamb is the wrath of God carried out against the wicked of the world, and is not manifested against the elect (1 Thessalonians 5:9). Therefore Revelation 6:17 cannot be the start of the Great Tribulation. Furthermore, Revelation 7:14 makes it clear that the Great Tribulation is before the Trumpet judgments, and is a part of the world chaos of the 2nd, 4th and 5th Seals.