Yeah I have no idea why rear McPhearson struts only work on rear-engine cars, when front engine cars used such suspension in the back as well. Then again there are various suspension types that could be added into the game if you ask me
With front-engined cars, semi-trailing arm rear suspension has similar attributes to McPherson struts (which can also be used in mid-engined cars), since it is cheaper than dual wishbones or multilink setups.