I would try doing this using a text layer.
Type some text dashes "-------".
Add a circular mask path to the same layer.
Turn the mask off.
Set the text to follow Along the Path (in the Path Options twirl down).
Using the Animation triangle thingy, click on Rotation to apply per-character-rotation.
Add more dashes if you need them.
Adjust the thickness using the "horizontally scale" control in the Character Panel.
Adjust the tracking in the Character Panel to adjust the distance between the dashes.
It gives you loads of flexibility, and the ability to make really nice animations too.

As explained in more depth here by @KylasaurusRex:
https://kylehamrick.com/textperiments-1