Since when is this hobby logical?
If you want to look at it from a logical standpoint, your needs would be fulfilled with two or maybe three watches and of course, to be practical, they should be quartz and not mechanical. But the point is that we are talking about wants and not practical needs in this hobby, or obsession to be more precise. By all means, if your opinion is that you need 10 watches, then collect 10 watches, if your magic number is 20, then collect 20 watches. THERE IS NO MAGIC NUMBER THAT WILL WORK FOR EVERY MEMBER!!!
I personally have way too many watches in practical terms, approximately 80, mostly ETA, but I consider myself as a collector. At a time or two I have considered thinning my collection, but every time I do, I find myself thinking why do I need to get rid of this one, so I guess I