That’s a really cool video, and really impressive roto work!
Perhaps competent isn’t the right word. What bugs me about her character is that she comes out of nowhere, we’re suddenly supposed to just go along with her plan (which the audience doesn’t know about), and then in the end, she saves the day?
I don’t think we’re supposed to go along with her, I think we’re supposed to be suspicious of her like Poe is. Then we’re surprised (like Poe) when she actually has a plan and saves the day.
I think the problem from a character perspective is that she does nothing to reassure anyone that she knows what she’s doing, creating growing animosity that leads to a mutiny.
One explanation that I thought while watching it was that she couldn’t trust anyone after being tracked through hyperspace. It reminded me of Battlestar Galactica, when they kept getting followed through light speed because someone planted a tracking device on their ship. If Holdo is suspicious of a traitor, she might keep her plans more secret. However, this is not really addressed in the film, so it comes off as a plot contrivance.