I think Bernie is the only one who may be able to win a majority of delegates for a first round convention nomination.
My guess is Buttigieg is just a stalking horse for Biden & Clinton, part of the plot. Buttigieg will attract less suspicion at this stage and will be the front man for the bullshit pulling.
My guess is the plan is Clinton at a brokered convention. Buttigieg & Biden pledge their delegates to Clinton. Bernie must be very strong and they have to take him out early before he gains voter momentum. I'd watch for Bernie 'supporters' who are plants going postal and MSM will use that to torpedo him.