Again, very true. I've been planning a shunting layout for sometime (4' x 3', so it will fit on the dining room table), I've done the baseboards out of foamboard (my back won't handle weighty wood), the Templot(gnash, gnash) and some C&L trackwork and was intending to run shunting diesels because they're small. Then the W4s come along.
The rest is in the future!