When Putin had the extension of his term of office formalized in mid-March, it could be expected that some changes in the government would come. There were two reasons for this. Firstly, there had been a standstill for too long and some kind of change was needed, and secondly, power had become too cemented in the Ministry of Defense over many years. With the end of the president's term, the government's time also ended, and making changes at that moment does not seem extraordinary, at least to some.
The appointment of Andrey Belousov as minister of defense actually shows dissatisfaction with the state of affairs. Someone from outside was most likely brought in to break the ties within the army, to have the officers be put «on coals», and this someone also had to understand numbers and the budget. Of course, Belousov’s appointment will no stop stealing in the Russian army, but it will slightly break established ties, because he is not in the so-called food chain. Also, an economy background will help to direct resources more towards war.
Shoigu was appointed secretary of the Security Council, which is headed by Putin himself, and his deputy is former president Dmitry Medvedev. Although this job does not come with a very major opportunity to manage the budget, this position has given Patrushev a lot of influence. His good rapport with and loyalty to Putin secured him a position in which he was even named vice president at times. Clearly, his power was greater than that of government ministers and often the prime minister as well. While Putin used the Security Council as an advisory body, it was a so-called siloviki government, where matters were actually decided.