If this is the reason, it can be questioned. According to your situation, there are 15 bidders participating in the bidding, which meets the qualification requirements. There should be many bidders entering the bid opening stage, more than three, which can not meet the requirements of re-tendering.
And the result is "reorganize the public bidding after re-subcontracting"? Explain that the reason for canceling the bid is not the problem of Party A and Party B, but that the owner did not divide the packages well at the beginning, and the problem can only be remedied.
As far as laws and regulations are concerned, there is no basis for re-tendering.
I don't know much about the winning bidder in the ball method.