There is a guy here who does cranks better than anyone so you give him the rotating assembly and take the block to a different shop.

The guy that turns cranks doesn't do block machining, but the shops that do blocks and cranks don't do great crank work so you have to split the parts up to get it all done right.

The guy that does cranks thinks the other shops here do sloppy block work so he freights his own blocks for his personal race cars to a shop in California where he used to live to get them done right.

One day these guys will retire and you'll settle for crappy work ,or have to mail you stuff off someplace else.