Armies can be compared to locust.
But in Revelation 9, the locust are not compared to armies.
Revelation 9:
4 And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads.
5 And to them it was given that they should not kill them, but that they should be tormented five months: and their torment was as the torment of a scorpion, when he striketh a man.
The locust insect like creatures are going to torment men with their very painful scorpion like stings for five months.
At least you acknowledge that locusts can be armies... That is real progress.
The people who aren't sealed by God are tormented by a
spiritual army. It is these people that place the abomination at the 6th Trumpet.
Dan 11:31 His forces will rise up and desecrate the temple fortress. They will abolish the daily sacrifice and set up the abomination of desolation.
They have an evil spiritual doctrine that fills them with demonic torment. Just like in 1 Sam 16:
15 Saul’s servants said to him, “
Surely a spirit of distress from God is tormenting you.
Why is it from God?
You think that the Dan 9:27 covenant is the Mosaic covenant, right?
The blessings and curses of faithfulness and unfaithfulness are derived from the Mosaic covenant, right? These are described in Deuteronomy 28 (among other places).
The 'locust' (spiritual) army are a punishment from God for unfaithfulness. It is described in Deuteronomy 28:42-52
42 Swarms of locusts will consume all your trees and the produce of your land.
43 The foreigner living among you will rise higher and higher above you, while you sink down lower and lower.
44He will lend to you, but you will not lend to him. He will be the head, and you will be the tail.
47Because you did not serve the LORD your God with joy and gladness of heart in all your abundance,
48you will serve your enemies the LORD will send against you in famine, thirst, nakedness, and destitution. He will place an iron yoke on your neck until He has destroyed you.
49The LORD will bring a nation from afar, from the ends of the earth, to swoop down upon you like an eagle—a nation whose language you will not understand,
50a ruthless nation with no respect for the old and no pity for the young.
51They will eat the offspring of your livestock and the produce of your land until you are destroyed. They will leave you no grain or new wine or oil, no calves of your herds or lambs of your flocks, until they have caused you to perish.
52They will besiege all the cities throughout your land, until the high and fortified walls in which you trust have fallen. They will besiege all your cities throughout the land that the LORD your God has given you.