You're right...this is true. However, they all have a "peak"...it's just not as pronounced as a conventional home's. The eaves I was referring too I should have just said "outside" or "exterior wall". True...they almost never have "eaves".

Point is though, look not only at the area right around the stovepipe but also upwards from there. However slight the pitch of the roof, water will still run down to a stopping point before it starts to drip straight down.