I think this depends on how you placed him when he scored most of those goals, also, when he was originally a ST(you can see that if the "ST" symbol is left, which means he was first a striker and than a AML, or right, which means he was first a AML and than a ST) my experience is that strikers who dont score a lot of goals score more if you play them in a different position like aml amr or amc.