People are bad at counting dogs

Here’s an odd phenomenon: If I am out walking our two dogs by myself, it elicits very little comment. People thinking nothing of one person walking two dogs.
If my wife and I are walking our two dogs, it’s the same. No comment.
But if my wife and I walk our two dogs and walk a friend’s dog as a favour, it gets some comment. “Lots of doggies!”
Two dogs and one person is a ration of 2:1 and gets no comment. Three dogs for two people is 1.5:1 and yet people see it as being more unusual.
You might think this is because people are commenting on the number of dogs per household- it’s my wife and I, so they think we have three dogs running around our home. Hence the comment.
But if you maintain three dogs and add a third person when a friend comes with us, it still warrants comment. At this point we are an even lower ratio, one dog per person, or 1.5 dogs per household, and people still say “lots of dogs!”, a comment they never make at the two dogs per person/household when I am by myself.
This carries on. If you add a fourth dog and a fourth person people see this as being even MORE unusual than the three dogs with two people. At this point they make comments like, “Enough dogs?” They see the absolute number and think we are crazy dog people, even though we are down to four dogs split up over anywhere between two and four households.
I’m not really sure what to make of this phenomenon other than to remember that when people use terms like “lots of” something, it’s ambiguous.