>>41208
Armies ordered off their subordinates into the field (Âncora, Kruel, Ladário). Divisions are meant to be field formations and only have field units, though in effect Bandeira commanded while Oromar Osório (1st Infantry) and Mourão delegated. Military Regions are the ones controlling conscription units, military hospitals and other administrative formations. When they do have combat formations >>36415 it's often support like AA or caçadores battalions, which are in effect territorial defense forces; many states in the order of battle are only defended by a single caçadores battalion at their capital. So the divisions focus on combat (nowadays they have proper brigades) and military regions on support and administrative functions.

The post-Goulart power struggle developed as follows:
Ranieri Mazzili was the new President but the highest power was with the "Supreme Command of the Revolution" composed of Costa e Silva, vice admiral Grünewald and liutenant brigadier de Mello, who also occupied the military ministries.
While heading to Guanabara at night on the 1st of April, Mourão Filho and Muricy heard on the car radio that Costa e Silva had taken over the Ministry of War and named general Ururahy to the Ist Army. At dawn he arrived on a Ministry full of sleeping officers. The Minister's cabinet was empty, Costa e Silva was soundly asleep in his old cabinet at the Works Department.
Mourão had big ambitions, of becoming Minister of War or at the very least, as the prize of a conqueror, the Ist Army. He was outraged at the opportunistic naming of someone else. Hence he and Costa e Silva argued over who should receive the Ist Army. Mourão was unconvinced but accepted Costa e Silva's decision as, although an usurper, he was still his legal superior.

There were now four contenders: Kruel, Mourão Filho, Costa e Silva and Castelo Branco.

Mourão's original plan was to march on Guanabara and storm the Ministry of War. That was still a possibility but he rejected it, refusing to go against the legal order. He distrusted Costa e Silva, already suspecting he wanted to be dictator. "Supreme Command of the Revolution" had an autocratic, "Spanish" ring to it - he even uses the term "El Supremo". Just look at his face. But he didn't know him enough to justify an attack, which would be on revolutionary, extralegal terms. He later wrote he'd have done it if he knew Costa e Silva better, and also thinks Muricy should've warned him.
Could he? He thinks he could. He had muscle, the original 2,714 men under Muricy at the Maracanã. Castelo Branco had none, Kruel was in the hinterland and Costa e Silva theoretically had the stronger Guanabara garrison through Ururahy but his grip was weak because he was new. Ururahy's regiments were precisely the ones that had defected. But the political situation would be different - coupist against coupist. There's little speculation on the subject but perhaps such an action would be poorly seen and end up in blood.

At Costa e Silva's request Mourão remained in Rio for a few days, but he had no more action. Castelist officers suggested he'd attack Costa e Silva, another poorly-covered event, but he refused. He despised Castelo Branco, who in turn scorned him. He returned empty-handed, disappearing from history books. He was brutally sidelined and lost the political fight.