While it'd be cool to have all runners, can you imagine how long it would take to find 5 villagers that all liked running? O.o
Yes, but I'm sure that will be no problem for those of us who spend hours in VF and go through hundreds of adoption applications for Miss Rainbow and then a few more hundred save-game-retries-again-and-again-and-againagainagain for Mr Spike...

(and then the new generation starts it all over again.)