Steve,
That's exactly how It started..... saying to myself that I only need 3 or 4 loco's, a few wagons and possibly 3 coaches. O gauge is an addiction so It never ends with just 3 or 4 loco's.....😁
I recently replaced the shelving in the office and SWMBO came home and stated that she wasn't expecting the shelving to run all along the whole wall. I just replied that it was safer so the loco's couldn't fall off the ends then she said "that now there were larger gaps between the loco's"..... I just smiled and slowly filled the gaps with more loco's. 🤣