Why not use the definitions God's inspired word gave us for candlesticks and olive trees to figure it out.
Rev 11:3 And I will give power unto my two witnesses, and they shall prophesy a thousand two hundred and threescore days, clothed in sackcloth.
Rev 11:4 These are the two olive trees, and the two candlesticks standing before the God of the earth.
What does Scripture tell us candlesticks are?
Rev 1:20The mystery of the seven stars which thou sawest in my right hand, and the seven golden candlesticks. The seven stars are the angels of the seven churches: and the seven candlesticks which thou sawest are the seven churches.
So if seven candlesticks are seven churches wouldn’t two candlesticks be two churches?
What does Scripture tells us olive trees are? (Words in blue parenthesis added for clarity)
Romans 11:17 And if some of the (Jewish) branches be broken off, and thou (the Gentile church), being a wild olive tree, wert grafted in among them, and with them partakest of the root and fatness of the olive tree.
Romans 11:24 For if thou (the Gentiles) wert cut out of the olive tree which is wild by nature, and wert grafted contrary to nature into a good olive tree (the Jews): how much more shall these (the Jews), which be the natural branches, be grafted into their own olive tree?
So the olive trees represent the Jews and Christians.
2 olive trees + 2 candlesticks = The Jewish and Christian churches.
I like this and would like to add to it if you don't mind.
Notice here that you have the two candles as two churches, namely the Jews and the Gentile.
I would take it a bit further.
Zec 4:2 And said unto me, What seest thou? And I said, I have looked, and behold a candlestick all of gold, with a bowl upon the top of it, and his seven lamps thereon, and seven pipes to the seven lamps, which are upon the top thereof:
Zec 4:3 And two olive trees by it, one upon the right side of the bowl, and the other upon the left side thereof.
Zec 4:4 So I answered and spake to the angel that talked with me, saying, What are these, my lord?
Zec 4:5 Then the angel that talked with me answered and said unto me, Knowest thou not what these be? And I said, No, my lord.
Zec 4:6 Then he answered and spake unto me, saying, This is the word of the LORD unto Zerubbabel, saying, Not by might, nor by power, but by my spirit, saith the LORD of hosts.
Notice here that the two olive trees are the word of God by the Spirit.
Zec 4:12 And I answered again, and said unto him, What be these two olive branches which through the two golden pipes empty the golden oil out of themselves?
Zec 4:13 And he answered me and said, Knowest thou not what these be? And I said, No, my lord.
Zec 4:14 Then said he, These are the two anointed ones, that stand by the Lord of the whole earth.
So they are Gods two anointed ones before the whole earth. these two anointed ones witness of the Lord.
So putting this together with your explanation. we have two churches that bare witness of God. the Jewish church and the Christian church .
What bares record of these two churches?
The Old testament is about God through the Jewish faith, and the New Testament is about the Christian Faith. which really are two views of the one faith.
Thus I believe that the two witnesses are the Old and New Testament.
by the way during the dark ages the word of God was hidden for 1260 years and at the end in 1798 the bible was publicly burned in the streets of France and they worshipped the God of reason. this took place for 3 and a half years. interesting that those historical dates match perfectly to the two time periods given in rev 11.
Blessings.