If you want to use randomly two types of light poles (with or without extension), currently is not possible. Although this feature is already implemented on RailClone 2.x (under development).
There is a rotation randomization added to the lightpole and applying the same randomization to the extension, but it's not aligning with the light pole.
If i understand well, are you using two RailClone objects on the same spline, one for the lightpole and other for the extension ?
In this case, would be possible to align both segments, if they share the same pivot point. Please, send us a test scene and we will check if everything is correct.