I'd been struggling to get a 4231 work the way I wanted in the lower leagues. I was finding I was
a) winning but conceding too many goals
b) most goals were all being scored by AF
But I've used this 424 above and moved to Right AF to SS (RCAM) and left everything else the same and bingo - solid defense, winning and good goal distribution - front 4 and LDM all contributing to the goal scoring.