The described 1973 scene is a bit of old PR trick
The soldiers were fully armed, not fully kitted, and the same with Merkava used.
Otherwise IDF would have to either employ exceptionally small soldiers, or warp time and space, or would not fight a long design battle around how many soldiers would fit into Namer.
Shermans were also used to transport numerous soldiers to a besieged unit on Okinawa and to evacuae he wounded, the record was IIRC something like 12 soldiers beng caried on one trip, but that does hardly make the Sherman an APC - and it certainly wasn't combat-capable in such a configuration.