Fred, When old our MoPar cars were new and shipped from the factory the arrows were positioned as said earlier. Now you must understand all the shoe webs and shoe lining thicknesses/drum diameters were all at a set factory standard that the factory engineered for all the new cars. Also remember that the factory new drum diameters were all at the new spec's !0/11/or 12" no over sizes so that meant that the brake anchors would all be set the in the same positions as all new tolerances were the same from the factory in most all instances. A lot of the aftermarket supplied shoes/linings were not manufactured to the same exacting factory dimensions. Also the drums wore to a larger diameter or were machined to a larger diameter after complete brake overhauls. This is where it was necessary in a lot of cases to do both major and minor adjustments for a good firm/high pedal(for 100% customer satisfaction)-IF the proper tools were available! At times these tools weren't available at some repair shops.
Another thing that usually isn't/wasn't done was to measure the drum diameter and then machine arc the shoes to match the drum diameter BEFORE doing a major adjustment.
If the shoe radius doesn't match the drum diameter you can never get the full face of the brake lining to be centered/adjusted properly to fit the oversized drum with any of the ammco or miller tools!
And yes, if the shoes aren't centered/adjusted to the drums, yes they will wear at the toe or heel prematurely-depending on lining thickness or drum over size diameter. Wouldn't worry bout that-Just check the shoe wear pattern after a few hundred miles to see were they are hitting and then adjust the anchors just a tad bit-all this for if you don't want to deal with making or buying the special brake tools. These double anchor Lockheed brakes don't automatically produce a hard pedal after a reline like all the more modern cars because the shoes are not free to float and center in the brake drums.
Bob