I think bearing clearance has an equal role in it. Lots of guys will stick a cam in and if it turns by hand, it's good, even if it's on the tight side. From building engines with extreme valve spring pressure on babbitt bearings (over 1000 lbs open pressure), I will tell you that mic'ing the cam and setting the cam bearing clearances like you would a main/rod bearing makes them survive.
I'm not saying every FE needs .0025" of cam bearing clearance, but I'm saying that if there's not enough oil present for a wedge, it doesn't matter where you clock the bearing.
In addition, every side oiler and aftermarket FE block does just fine with the hole in the 6:00 position. With really high pressure, you can groove the back side of the bearing and clock them, but on "normal" situations, the 6:00 hole does just fine.
On another side note, with the side oiler and aftermarket blocks, where the rockers oil through the pushrods, I will turn the cam bearings 90° on 2 and 4 so that the oil feed to the head is blocked. It's quicker/easier than tapping the feed hole in the block or trying to restrict/block at the cylinder head.