Questions About Dispensational Pre-Millennialism

I've asked:

When will the people who get saved during 'The Great Tribulation' and who survive 'The Great Tribulation' begin to experience immortality?

What Scripture-passaged describe that event (if I Thessalonians 4, I Corinthians 15 and Revelation 20:4 describe a Pre-Tribulation resurrection or the resurrection of saints martyred during 'The Great Tribulation' only, and if Revelation 20:5 describes the resurrection of the wicked only, after 'The Millennium')?

And what do you have to do to a Scripture-passages in order to 'see' that event described in it?

Someone answered: 

Only those saints who "die physically" during the Tribulation will be immortal during the Millennium. All saints who survive physically to the Millennium will enter into the Kingdom in mortal bodies.

To which I replied:

So that presents a seeming contradiction. 

It would mean that pretty-much "All Israel" will be mortal, during 'The Millennium'. 

Because according to Dispensational Pre-Trib Pre-Millennialism, "all Israel shall be saved" either during 'The Millennium' or at 'The Second Coming' or during 'The Great Tribulation' - AND Israel shall survive the Great Tribulation because they shall be spared from annihilation by the nations at the 'Second Coming'.

Whereas 'Tribulation Saints' among the Gentiles don't have any prophetic promises of protection. Many of them will be martyred. But because they will have been martyred during 'The Great Tribulation', you say they won't be mortal during 'The Millennium' - but the saints who survive 'The Great Tribulation' - most of whom will presumably be Jews, because they have the prophetic promise of protection - "all Israel" - will be mortal. 

So that would put saints for whom "the days will be shortened" at a distinct disadvantage for a thousand years! They would have been better off getting martyred, so they could be immortal and enjoy the entire 'Millennium', instead of being subject to mortality and die and miss out.

And the nation which will have the highest proportion of mortals, during 'The Millennium', will therefore be "all Israel". Because the entire nation will have been saved and yet survived 'The Great Tribulation'. 

So that would mean that a majority of people in other nations; plus 'the Church' (which was Raptured before 'The Great Tribulation') will enjoy privileges over national-Israel during 'The Millennium' - they will have glorified bodies; they will not be subject to mortality; they will get to enjoy "The Kingdom of God" for the whole thousand years - whereas "All Israel" will still be subject to mortality, because they were spared from death during 'The Great Tribulation'.

So - they were spared from dying during 'The Great Tribulation' - but miss out on immortality during 'The Millennium'. 

The contradiction in that, is that according to Dispensationalism, 'The Millennium' is necessary in order to fulfil promises to Israel. 'The Millennium' is largely meant to be centred on Israel. And yet, you would have Israel as the most disadvantaged of all nations, during 'The Millennium' - disadvantaged also in comparison to the Pre-Tribulation Church, because Israel would have the highest proportion of mortals of any nation - because they will have had the highest proportion of survivors of 'The Great Tribulation'. 

To me that sounds fraught with contradictions. 

I also said to someone:

It seems kind of self-defeating, doesn't it.  

A Dispensational model of 'The Millennium' is created in order to put Israel at the top again (to solve the imagined dilemma of unfulfilled promises; and to avoid that dreaded 'Replacement Theology') - only for Dispensationalism's own systems to mean 'all Israel' will actually remain the most disadvantaged of all saints during their own 'Millennium'.

Additional Remark:

Dispensationalism insists that 'The Millennium' is necessary in order to fulfil Israel's promises. But wouldn't their own system keep Israel at a disadvantage to the Church during the Millennium? Because 'all Israel shall be saved' and survive 'The Great Tribulation', they say - therefore Israel would enter their own Millennium as mere mortals, while the Church would reign immortal for the duration.