This is a second interpretation of the first five verses, but not a different one. We have a preliminary interpretation in verses 6-7, and in verses 8-10 we are presented additional information and interpretation of the seven lamps.
The interpretation in verses 6-7 concentrated on "by My Spirit," making sure we get first things first. God, by His Spirit, will be behind all of this; it will be done by grace. We must understand this as priority one when we consider the work of the Two Witnesses. They are servants, and they follow the lead of God's Spirit. That is how their work will be done. That is their mind as well; they will not take credit for what they accomplish. They will know that it is done by God's Spirit.
Verses 8-10 shows that God really has Christ in mind (more than Zerubbabel, who was just a type). We always have to look at things like this and realize that there are types of Christ in them. Zerubbabel—though he is a type of one of the Two Witnesses—is really a type of the true Savior, Jesus Christ. Christ is the true King, and we can never keep Him out of these things.
Christ is building a spiritual temple, and He finishes what He starts. We can paraphrase verse 9 as, "The hands of Jesus Christ have laid the foundation of this temple; His hands shall also finish it." We could go back even as far as Creation and recognize that He was the One who created everything. He started the process that will end in salvation. He will complete the job and bring God's purpose to pass. As far as laying the foundation goes, He did that in Old Testament times, or we could bring it forward as when He gave Himself as a sacrifice for our sins to establish our relationship with God the Father. No matter where we see the starting point of the spiritual Temple in history, He will complete it.
Philippians 1:6 says He who has started a good work in you will finish it. He will complete it. Zerubbabel's completion of the physical Temple in 515 BC is just a sign, if you will, that Christ will finish the spiritual one.