Why do some people believe that LORD cannot predestine?

Is not the following a picture of four angels predestined by the LORD?

Revelation 9:14 Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates.

  15 And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men.

These four angels were prepared in advance, for an hour, and a day, and a month, and a year, yet to come.

And they have been bound in the Euphrates for thousands of years, waiting for the time when they are loosed.

This sure looked like the four angels were predestined for this one thing, to slay the third part of men.

The four angels come out of the Euphrates, but where do the horses come from?

What is written of the horses, does that sound like any horses that we see here on the earth, on any given day?

Revelation 9:17 And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone.

  18 By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths.

  19 For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt.

I know that many say that the horsemen are Chinese,

because they believe that the number is the same as what Mao said that is how many soldiers China could raise,

also, because they believe this is also speaking of the kings of the east and the dried up Euphrates, in chapter 16.

Even if the horsemen are Chinese, are these what Chinese horses look like?