If you loose a T70 or stuart to an MG42 you are really really bad.
Incendiary ammunition needs to be reloaded, which takes time and you can see if someone's shooting....stopped shooting and loading the the new ammunition.
Ah and btw its not like "BAM" the MG42 hits the field and is vet1. Enough time to use your M3 and WC51. Oh and for the AEC ever heard the word smoke?