In Batei Midrashos here (second paragraph) he notes that Bilaam thought that Bnei Yisroel would be redeemed from mitzrayim and given the Torah through him. When all of this happened but through Moshe Rabbeinu it made him intensely jealous.
Just listened to shiur by Rabbi Eytan Feiner, who when giving it says that Chayei Sora even though it has a name in it, it not the list of parshiyos that are just names. So I am going to summarise the shiur and hopefully it is understandable.
He says that these 5 people all have in common a turning point in Klal, that excludes the spies and the egel since ...
Rashi on Balak 23:10
Who counted the dust of Jacob or the number of a fourth of [or, of the
seed of] Israel? May my soul die the death of the upright and let my
end be like his."
Who can count the dust of Jacob: As the Targum [Onkelos] renders, “the children of the house of Jacob, [concerning whom it was stated,
'they shall be as many as the ...