This Overwrite removes all Stirrup for horses.
You will have no Stirrups for horses while riding at all.
If you still want them sometimes, you have to remove this CC!
To make the look perfect you can use my No Saddle CC for your Horse. It can be found in Accessoires and can used instead a normal saddle:
https://legacy.curseforge.com/sims4/pets/no-saddle