It is obvious that the identical korbanos were the right thing to bring- that they were mechavein to Hashem's will. So that means that Hashem intended for every one of them to bring precisely קערת כסף אחת שלשים ומאה משקלה מזרק אחד כסף שבעים שקל בשקל הקדש שניהם מלאים סלת בלולה בשמן למנחה כף אחת עשרה זהב מלאה קטרת פר אחד בן בקר איל אחד כבש אחד בן שנתו לעלה שעיר עזים אחד לחטאת כג ולזבח השלמים בקר שנים אילם חמשה עתודים חמשה כבשים בני שנה חמשה. But their decisions about what to bring were totally independent. That means that although their ultimate choice was predestined, each individual made his decision on the basis of a lifetime of personal experience and hard-earned wisdom and spiritual achievement that informed his choice about what was the best and most appropriate korban they could offer, both as individuals and in their capacity as nasi of their shevet.
You have these twelve separate individuals, scattered all over the Machaneh Yisrael, sitting in their tents and pondering what the best and most meaningful Korban they could bring would be, and these twelve people decided, for twelve different sets of reasons, to bring exactly the same korbanos. Visualize Nachshon ben Aminadav sitting on the east side of the Machaneh Yisrael, carefully thinking about what he should bring, and seven miles to the west is Alisha ben Amihud, thinking about the same thing, and the light bulb goes on in both tents- and ten other- that they should bring "kaf achas....." Biologists would call this convergent evolution. In Chazal, it's reminiscent of the story in Sukkah 53a where Shlomo HaMelech quickly sent his two scribes to Luz because he heard that the Malach HaMaves was after them, and ironically it turned out that the Malach HaMaves had been told that he could only take their lives at the gate of the city of Luz. It was Shlomo's personal choice, but what he chose was predestined and inevitable.
The Satmarer Rov takes this approach, with a slightly different perspective. See his Divrei Yoel on this parsha, starting on page 147, paragraphs ו) ויהי ביום and וביארנו הענין, and then page 151 beginning from ומעתה. He uses it to illustrate the classic yediah/bechira idea of foreknowledge not contradicting free will because the foreknowledge is not based on an understanding of the inexorable and inevitable consequence of the facts of the present, but rather a supernatural awareness of what the future holds; he sees it as meaning that each person has innate proclivities and experiences which encourage (ensure? predetermine?) certain behaviors.
It's interesting how easy it is to overlook this powerful example of yediah u'bechira. Ironically, some of our readers will come away from this thinking that they knew it all along. That's what the Briskers want in their Divrei Torah. Before you know the pshat, it was impossible to see. Once you know it, it appears to be self-evident.
אמר רבי בנימין הכל בחזקת סומין עד שהקדוש ברוך הוא מאיר את עיניהם