Are these lines going to be concurrent?

Revelation 11:2 But the court which is without the temple leave out, and measure it not; for it is given unto the Gentiles: and the holy city shall they tread under foot forty and two months.

  3 And I will give power unto my two witnesses, and they shall prophesy a thousand two hundred and threescore days, clothed in sackcloth.

If so, will the two witnesses be prophesying during the 42 months that the Gentiles will trod Jerusalem under foot?

Are not those 42 months of the Gentiles during the great tribulation?

Are there some who think that line 3 happens 3½ years before line 2?

Or are there some who think both lines 2 & 3 happen before the 3½ year great tribulation?

i.e. do they think that there won’t be Gentiles trodding down Jerusalem during the great tribulation?