To get the angle between holes to have different values, for example the angle between two holes is 30 and the angle between two other holes is 40, you can control the locations with a table patten. Start out by creating your feature with an angle that can be used as the increment value for the pattern. When creating the pattern start out creating an axial pattern; in the dimensions tab select the angle value as a value to increment; change the pattern type to table, this should give you two values to specify, the increment angle and the rotation angle direction. If you have three vanes with the first one starting at 80 with angles of 30 and 40 between the vanes, specify the rotation angle direction as 80 and the angle increment as 0 for the first vane (specifying a rotation angle direction of 0 and angle increment of 80 will put a vane at the same location but I'd use the first mentioned values for consistency, for the second vane specify the rotation angle direction as 80 and the angle increment as 30, and for the third vane specify the rotation angle direction as 110 and the angle increment as 40. This should create three vanes at 80, 110, and 150.
