So Mallard, what do you really think? :-D
On the original issue of this thread, I think the answer is somewhat area and species specific. On a big line, like oh say 100 miles or so it would be imparctical (imposible) to set all at once. On predator lines, I try to hit the hot spots (traditional / obvious locations) first and fast covering the entire area. Then let the coyotes etc tell me where I missed a good location. By taveling the line I get to locate those little hidy holes and travelways that pay big dividends in fur.
With any critter that travels widely, you will be more llikely to catch him if you have traps in various locations over thier range; I'm thinking on a timely basis here. Now, enter the size of the range in particular geographical locations, i.e., southwest vs upper mid west. Also, factor in seasonal movements and prey shifts and movements. Sometimes its real hard to effectively scout preseason, if you will.