Zoronami People forget that there are big differences between Ainz and this protagonist.
1) As you said, this character doesn't know the powers and how they work, so he can't use them. He doesn't even know what powers he has.
2) Ainz has experience of how the company management works and therefore knows how to speak to his subordinates. This character was a boy who went to school.
3) Even if he sometimes makes mistakes and gets scared, Ainz has the emotion suppressant that makes him calm down immediately, this character does not.
4) Ainz is by nature selfish and the fact of having the suppressor of emotions and the resources to do it have made him a true overlord. This protagonist would not want to kill anyone because he grew up in peace and with a higher morale than Ainz's.
5) The subordinates of this protagonist joined the Overlord because they wanted to eliminate humans, who for one reason, who for another and had become accustomed to following a certain way of doing and will turn if they understand that what they have in front is not the original overlord (we saw it in ch. 3 and in this). Ainz's subordinates have been programmed to obey him and if he should make mistakes they (especially Demiurge) will find a reason behind a certain action. In practice, no matter what Ainz does, it is enough for them to continue to govern them and make Nazarick prosper and if this means saving races considered inferior so be it.