Merit

Nobunaga promoted his captains and soldiers on merit, not linage and it proved to be a success.  He hated the the old order on how the long established families kept the the ones who did the work down and out.  He change it.  If you did well on the battlefield or other related works, you were rewarded.  At the same time he demoted, banished, or killed high or low for not doing their job.  Nobunaga was not afraid to hire someone on the outside, like the Men of the Fields, Hideyoshi, or even Akechi Mitsuhide to do the dirty work for him.  It proved to be extremely successful.  Competition created success for Nobunaga.

Neil McMullin, Oda Nobunaga and the Buddhist Institutions, p 84

"Breeding and proper blood lines meant nothing to Nobunaga.  Together with such patricians as Niwa Nagahide and Hosokawa Fujitaka, he added to his inner circle such low born people as Toyotomi Hideyoshi and Akechi Mitsuhide.  Oda promoted people on the basis of their ability, and demoted those--no matter what their breeding--who failed to meet his expectations.  A good example of the latter was Nobunaga's punishment of Sakuma Nobumori, a person of noble family and one of Oda's top ranking generals, for his poor performance during the siege of the Honganji citadel from 1575 to 1580. Persons, whether they were bonzes, kuge, or peasants, who showed loyalty to Oda were rewarded, and those who opposed him were destroyed."

Nobunaga also banished Hayashi Hidesada and Ando Morinari for not doing their job. Even maidservants were put to death for skipping work.  Yet, someone like Maeda Toshiie who was banished and allowed back in the Oda house due to his merits on the battlefield at the Battle of Moribe in 1561.  It must have been difficult for the old guard as well as the newbies to work for Nobunaga.  You had to perform or else.  Knowing your boss was not afraid to hire someone on the outside added the stress.  That being said, if you were consistent on the battlefield and the like, you were well rewarded.

Nobunaga no tame!