Jim:
We will probably never know the details of who exactly routed Merion East in the early days of 1911. Obviously, the most logical thing to assume is that Hugh Wilson and his so-called "Merion Committee" routed the golf course. Flynn at that time was only 20 years old and was basically a glorified laborer who'd come to the old Merion Cricket course in Bryn Mawr that year or perhaps the year before.
But if one wants to use commonsense it would tell you that if the club had sent Hugh Wilson to Europe for a solid seven months of architectural study, sketching and such, the club obviously meant to use him to lead the committee to route and design the golf course. Otherwise, what and why did he go to Europe and study for seven months for?
Furthermore, I hope no one takes this the wrong way but routing a course on Merion East's property is pretty obvious compared to most other courses. In other words there's not that much lattitude to what the routing should be and can be---at least not in the sense of the basic direction of the holes. Somebody could've gone in reverse, of course, but that's not the point---the point is the holes would still lay out along the same corridors even if they were played in reverse. The reason is Merion East's site is a long L shaped thing on both legs of the L and there's really no ability to go perpendicular toteh way most every hole that's out there. If they did that they'd have a whole bunch of really short holes.
Doing a routing, in my opinion, is sort of like putting the pieces of a jigsaw puzzle together and the point is the clubhouse side of the L is less than 300 yards wide and the other side of Ardmore Ave is just about 300 yards wide. That's why there's only one hole on the course that goes perpindicular to the length of both sides of the big Merion L---eg #10---#11 sort of does but it swings left and goes to the end of the L as does #12 in reverse.
Bill Coore calls routing "taking a golf walk" and the routing golf walk at Merion East, as great as the course is and as great as the routing is in the broad scheme of routing golf courses, is pretty obvious when you think about it. Of course you can start the tees and stop the greens at any point along both legs of that long narrow L that is the Merion site but I think you know what I mean here about the routing being a pretty obvious "golf walk" for those that did it back in 1911.
There's that interesting story posted above about how the 15th and famous 16th came into being at the top of the Merion L. They ran out of room for two decent holes in that area so they traded land they owned across the street (now residences) for the land that is not about the last 100 yards of the 15th and the first 100 yards of the 16th.