Obviously the Naval extremists would have to make alliances with political extremists, Army factions and Imperial court factions to stay in power, and it's not like they are going to starve the Army of funding entirely, or dictate a withdrawal from Manchuria, or even restrain all Army expansionist ambitions on the continent.
It seems to me that a Navally-led junta though would up the budget for the navy, end participation in the 1934 naval talks before it begins, and so on.
It remains to be seen whether that would be enough for the Navalists, or if their growing power/self-confidence creates peer pressure for them to demonstrate their power by restarting the Shanghai incident, seizing Hainan, or taking other action along the China coast or against the DEI.