I was thinking in doing one myself too, but the pod is that Washington Luis is killed in 1928 and his Mineiro vp is capable of negotiate a deal between the two sides, with Julio Prestes being elected in 1930.
Washington Luís and his 'my way or the highway' attitude were a big obstacle as I understand it, yes. You would still have to face two problems: the mineiros were quite adamant on having one of their own as the next president, and the paulistas were convinced a mineiro president would screw them as much as Artur Bernardes did. Still hard to get a deal, but (a bit) easier.
As for the OP's idea: see what was said about paulistas and mineiros above. The mineiros would have to give some pretty big concessions to the paulistas, and that is assuming they get past Washington Luís stubbornness(going around him to negociate would be difficult, but could be done, I
think). My guess is you would end with an Andrada/Prestes(or some other paulista) ticket as part of the compromise.
Upcoming Problems for the Republic: The Tenentistas are rising up in the military hierarchy - at least one of them is a Lieutenant-Colonel (Góes Monteiro) by 1930. In OTL, the military command ended up ousting Washington Luís because they couldn't count enough on the loyalist part of the Army to stop Vargas and the Tenentistas who supported him(as they were flipping a lot of officers to either outright join them or look the other way as they passed). If the Tenentistas rise(and it's quite likely), the government won't probably be able to stop them.
There is also that little matter of Brazil(and the State of São Paulo) being really fucking bankrupt as a result of the 1929 Crash.
Regarding the Jedi: The Sith don't have shit on Brazilian politicians. Palpatine is an amateur compared to them.
