The percentage of performed actions (Assassin's Creed Rebellion)

Anyone figured out how to work percentages under the action and if they work at all.
Example

Personally, I have neither a role to play, for the sake of interest decided to choose only actions with a minimum percentage such as 5 or 30% in most cases if the hero figure Power is greater than recommended for the mission it will perform an action always successfully otherwise if the power is below the recommended even if the percent is 80% then it is likely to make a mistake.