The horseman cannot be antichrist, he comes after the seals.
The first horseman is the chain of human governments setting out to conquer the people and their rights through their “Mystery Babylon” cliques.
Part of Revelation has to be past, and part has to be future to satisfy Yeshua’s commission to John.
In answering you, this is where we tie in the subject of this thread, the sun and moon darkened in Joel and Acts 2.
If we look at the sixth seal, I see it describing the astronomics of the day of the Lord, “immediately after the tribulation of those days,” Matt. 24:29, closing out the end time great tribulation.
And what precedes the day of the Lord but the great tribulation itself? a time period of three and one half years. Which is what I see described in the martyrdom of the fifth seal.
But before you can have the 3 1/2 year end time great tribulation you must have the central figure of it, the antichrist, which is what I see described in the first four seals - his going forth.
Thus by working backwards from the sixth seal, the day of the Lord (sun darkened moon turned to blood), to the first seal, it, in my view, indicates that the first seal has to be the end time antichrist.
This, of course, is not the way historicists interpret the seals.
White horse - Everyone assumes these are all evil... Step away and look:
The white horseman is given a crown. And he has a bow. Who has a bow in the Tanakh? Ephraim. This is Ephraim going forth to become a 'great nation in the midst of the earth'. Everyone understands the 'death of the testator' from a Christian point of view, but who looks back at the promises to Israel? They too require the death of the testator - The blessings are inherited down the line, but who is the testator? Abraham? No...
The white horse culminates in Britain and the US... the western Republic form... those who fled from before the dragon into the wilderness.
The red horse culminates in communism.
The black horse culminates in Mohammedanism.
And the green horse presumably is the 'new world order'.
These are the end-time alignments/philosophies. And they rose to world power according to their progression.