Very nicely made snowman.
https://goo.gl/images/smWJ5w
But it has no arms.
When we did it, we pretty much always tried to do it from three balls of snow, as demonstrated here. You do have to have the right type of snow, though, as Chronos says. Gotta be good wet, packing snow. (If it wasn’t, we just wouldn’t bother.)
Agreed. I’ve never made a snowman from a pile of snow. If it wasn’t “rolling snow” we just didn’t make snowmen.
Last snowman I made had four, but two of those were heads.
Didn’t we used to have a user around here with a name like “TwoCarrotSnowman”? 
Sometimes 2 is all you can do. Adding a third only makes it look worse. If you dress it up properly, it’s still a snowman.
While it’s true that Frosty had 3 before he came to life, he later only has two when his hat is taken away in July (assuming my memory isn’t faulty). It seems 2 is his natural state, after having reformed.
Also, this is correct. Two-tier snowmen just look misshapen to me. You need a head, a torso, and an ass/leg/base. To me, a two-tier snowman looks all sorts of wrong.
Two-teir snowman look short and fat to me, but not wrong. Three-teir snowmen actually look wronger if they’re the standard type with a larger bottom ball than the middle ball - legs/bodies don’t work like that.
Of course, the OP is specifically asking about Frosty. Frosty has a head ball, a single body ball, snow-formed legs and arms, a scarf, and a hat with a flower.
Speaking as the mother of a son, it’s because y’all are cute as buttons.