Amsoil do not follow any standard - they actually refuse to endorse any of their products against any factory standard.
MB themselves fill their cars with Shell lube oil products at the factory, for your reference they have provided their oil spec data sheets online - with an exhaustive list of products that meet spec.
still - I would trust a brand being backed in local market rather than khayp maal like mannol, profi or meguin etc.
I have experienced this - A small shop in Karachi started selling redline oils, they sold something to a customer whose engine failed due to the wrong product etc etc.
car owner contacted shop - they said get lost, car owner contacted redline, they asked for the bottle identifier to trace the batch etc etc. , They told customer to pound sand as there is no presence of Redline sales in Pakistan.