I doubt either would be a slouch at any role you throw at either, truthfully.... ; although if leaning towards many cores for reasonable cost, most opt for the 1700 running at 1800X speeds to save $150-$175 or so...
If your simulations utilize all cores, perhaps the R7 will fare better, but, if clock speed still is equally important, the 8700X might fare slightly better in speed, you'd have to research those specific software comparisons perhaps at forums that specialize in such usage comparisons...