There IS plenty reason to get hung up on it. What IF the person assembling is not aware they are timing up on #6? They drop the distributor in 180* out.
If you are on the compression stroke at TDC and you set the rotor under the #1 tower of the distributor cap, they will be good. Never have I worried about 12 o'clock and 12 o'clock. It is irrelevant.