I say just copy what CoH1 did. Give the squad leader a rifle with the model of a smg. Adding another man onto the squad is enough already, giving said man a better weapon than the rest of the squad is just too much imao.
The reason the VSL gets a better weapon is to make the upgrade more attractive, compared to g43 and mg42. Just a fifth man is too underwhelming for grenadiers, even with the slight RA and CD buff.