Setting The Tone

Moshe's blessings begin with Reuven and go to Yehudah. Shimon is skipped altogether while Levi plays second fiddle to both. Even though Levi has a longer Blessing ,there seems to be something out of order here.
What Moshe sees is the need for each tribe to be happy within its own perimeters . When they try to obtain what isn't theirs there becomes chaos and tragedy.
In truth the greatest blessing is reserved for Yehudah who is the father of the Davidic Dynasty, hence the Messiah ,the ultimate Jew, the ultimate human being. Everyone else is the Messiah's
student or underling. However, by doing so there is danger of jealousy and collusion to destroy
the role of the Messiah.
First on the agenda is placating Reuven the first born of Israel. Let Reuven Live and not Die seems redundant until you realize that the basis of the opposition of Dathan and Avirum to Moshe was mostly from their view that the Reuvenites should be the leaders.
Therefore the Blessing is that Reuven live meaning- He shall enjoy his role as one of the Tribes and shall not die through the jealousy that has hounded and prevented his growth until now.
By letting go of fantasies that are unrealistic Reuven will flourish.
The next tribe to deal with is Moshe's own tribe -the Levites. In the future Moshe sees how usurping the role reserves for Yehudah will be tragic for both the Levite Kings and for Israel. The Hasmonean Kings were directly responsible for the Roman takeover and the subsequent destruction of the Second Holy Temple.
Hence Moshe tries to appease them by stressing the importance of the role that the Levites will play as the spiritual guides of the populace. Furthermore by announcing that usurpers of the Service that is designated for Levi will be punished serves as a hint that the same will hold true for the Levites that take over Yehudah's role.
Shimon is altogether not mentioned because by omission Moshe hints that they still have to correct the weakness of Shimon which is jealousy of anothers' good fortune. This will allow an immediate acceptance of Yehudah's primacy by Shimon.
The next tribe-Benjamin had to be placated because of its' unique role as the beloved of G-D. For G-d chooses the area of Benjamin to have the Temple in. For that reason it would appear that the leadership should also be from Benjamin. In fact the first king is Saul of Benjamin .Nonetheless, because Benjamin is not a self starter but a follower of G-D he cannot lead.
Yossef is next . He will be successful beyond belief . The conquest of Israel is his role. However, in order to be a leader of men you must know their sufferings and limitations . His success makes him too critical to lead . The Messiah of Joseph will start the process of redemption . However it is Yehudah that will emerge as the ultimate teacher and leader.
Thus Moshe in his Blessings sets the tone for the future. He tells the people "all of you will have your special role. If you see yourselves as part of the unit of Israel you will be successful beyond your dreams. If, however, you put your own goals before the benefit of the whole people ,you will know heartache.
This is the reason that the Blessings begin with the words "and there was a King for Yeshurun (Israel) only when "Yachad Shivtey Yisroel"-when the tribes are unified for one purpose. That is, the role that G-D has preordained . Yehudah will lead and only then will we all reach our potential!