the sims 4 roof trim

@larsyx 

I tested this and found pretty much the same thing you did.  And it's just not the big trim, it's all of them.  For some, it's hard to see but when you zoom in close, you can see it.  In the attached pic, the tower in the front is with no trim and the other towers show the various trims.

I did find a way to get close to the look I think you were going for though using a belt course though.  It's not quite the same as there are fewer choices but the dental belt course looks pretty decent.  So that may be a way you can use to get the look you're after.  

Hope this helps.