190E 2.6 vs nearly all other models up to 2014
 

What is the deal with the rear control arms (rear spring link) of the 190E 2.6 model vs all the other models from about 1986 - 2016? Pretty much all models from '86 - '15 can have these control arms interchanged, including the 190E 2.3-16v, but it seems like the 190E 2.6 is left out. What is the fitment reason, if any, why this part won't interchange even though they both use the same exact bushings?

Do you mean this one?
https://images.app.goo.gl/y6LPQkioc9dXH8sF9

As far as I know there is only one version applicable to all W201 models.
But I don’t know whether the W201 part is different to the e.g. W124 part.
But I rarely believe that exactly the same part was used up to 2016 models.
W202 and W210 share various parts pf the rear axle/suspension with the earlier models but the later models have different parts.

For the W124 models there is a difference between estate and all other models (sedan, coupe, convertible).

Since W201 was the first car with the multi-link it might make sense that that car is a slightly different design from the rest.

All the 190's except the 16v get the early edition link 40 uses listed

the 16v,124, 202 and more get the later edition 502 uses listed