I agree with the "two types of pipe owner" theory. I am lucky in as much as the criteria I need to fill is rather simple. Here's the logic behind the 10 pipes I mentioned before.
A) I only want what I need. I have no need to collect. I just need them to work.
B) Pipes must "sit". Resting the stem on a matchbox to keep the bit off the surface is acceptable, lying down on it's side or needing "apparatus" to stay upright is not.
C) Three dedicated pipes, English, Lakeland and aro. Smart(ish) briar preferred for Lakeland and aro. English is irrelevant - if I don't care what it smells like, why should I be bothered what it looks like.
D) Three general use pipes, ghosts welcome. Small, medium and large capacity. Cobs and cheap hardwood is the order of the day, as careful handling will be optional. Aesthetics are irrelevant.
E) One unused pipe in reserve
By this reckoning, I have three pipes too many. Two are clays, and no doubt gravity will kindly eliminate them from the line up at some point.
The last is an off-brand Baby Wellbent briar, which doesn't sit, so doesn't get used much, but is very pocketable and sometimes gets carried for "emergencies". Not a pipe that is needed, but one that can be useful all the same.