To begin with: "Aggressive pricing" is another word for "underestimated costs and time". And the costs are not all on Boeing, as Boeing does not pay for unplanned life extensions for inventory tankers. And this is a serious business, so dismissing such a comment with a blase "shoulda coulda woulda" is a mite sophomorish.
And, clearly, C-5M and KC-46 have one important common feature: underestimated cost and time. The A models had been flying for 30 years and their condition should not have been a mystery; if there were internal issues that might not be found until teardown, margin should be included. We've been finding nasties in old airplanes for decades.
There was one difference: the KC-46 bid was low in order to win, and the C-5M bid was low in order to get the program started.
As for the so-called nonconforming Airbus bid...
Since the two rival tankers had already satisfied 372 mandatory performance requirements, price determined the outcome and Boeing emerged victorious.
And that's according to
Boeing's own consultant.