Ellis for Bogut seemed like a great move right off the bat because the team was going nowhere AND it allowed them to tank enough to barely (i think by way of an unlikely Lakers comeback against us in the final week) keep their first round pick that year. Less obvious was how good the side moves around that trade were going to turn out... Stephen Jackson comes back in the trade with Bogut, and the W's immediately turn around and ship Capn Jack's expiring contract to the Spurs for Richard Jefferson's bad deal and their #1 pick. That pick turned out to be Festivus, and set up the Green pick at #35. If they hadn't had that #30 to grab Ezeli, maybe instead they miss Ezeli, grab some other big at #35, and get neither of them. That trade was the turning point that allowed the franchise to transform from the perennially defensive doormat to a defensive powerhouse.
Looking back at all the moves that allowed the Warriors to get here is a pretty crazy journey. I roll my eyes at other fans who still today say shit like "If we'd only taken Drummond instead of Barnes how good would we be.... " when so many of the moves they made turned out perfectly.