Military junta? Other authoritarian regime (Imperial Restoration, general von X leads the way...)? The Soviet Union? If avoiding Hitler won't be an option, then my recommendation is axing any 1932 or earlier plans. It raises unnecessary hopes.
Although Hitler is practically unavoidable in 1933 it still makes sence to make a scenario starting earlier than 1933. It will raise understandable hopes for those who want to play such nations as France, Finland and Poland. With more time to prepare, who knows, maybe they'll have some chance to survive the upcoming aggressions. For Mannergeim and Pilsudski/Rydz-Smigly the clock is ticking very fast. Every additional month is more than valuable for them.