At this point it seems Bibi is ready to split the premiership with Gantz 50-50. I've even seen reports that he is willing to give Gantz more than 2 years, as long as Bibi goes first.
So, how about a coalition of the right- 55 seats, PLUS Gantz breaks off from Lapid with his 15 seats (since regardless, most think those 2 will never run again together), and they split the Premiership 50-50.
It will be a stable coalition of 70, right wing/center, and Gantz is the Incumbent prime minister when they hit the polls in 4 years from now.
If he does a good job, he may even win reelection, and if not, the Likud will take it back in 4 years.