[Marcello]

I remember reading a study on the effect on proxy fuzes a long time ago. IIRC the increase in lethality, compared to contact fuzes, varies widely depending on target disposition. The greatest increase,by some ludicrous high percentange, was against troops laying behind vertical cover but without overhead protection. The smallest was against troops standing in the open, though still in the double digit range; in any case it is not how you want be caught by an artillery strike.