They couldn't be all on Earth.
But they were at one point. Unless they gave Visser Two a human host while he was visiting Earth--which I don't see the reason for-- we can assume that Visser Two was also stationed on Earth, and given a very important human host. Visser One made regular appearances. And then, of course, Visser Four was sent to Earth.
Remember what Ax says of Visser Four in Elfanfor's Secret? A Yeerk doesn't get to be Visser by being stupid.
Yea, but Visser Three eventually became very, very stupid. And Visser Four...only slightly below Esplin on the dumb scale.
Any how, it's a good thing that I checked through the forums, otherwise I would have created a pointless thread. I was thinking these past few days about the whole "what other host bodies did the Vissers have" and was going to make a thread dedicated to speculation.
One could assume that a majority of the Vissers have Hork-Bajir and Taxxon hosts, given that the Yeerks have successfully enslaved those races. The Council is mostly Hork-Bajir and Taxxon. The Inspector was a Garatron, and he was considered for the Council. And we know of at least two Vissers with human hosts (Visser Four doesn't count, as he was demoted). So that's two humans and an Andalite. I'd assume that human hosts are a minor phenomenon amongst the forty-seven Vissers--if not only because I think having most of them be humans would be boring.
What do you guys think? Any Sstram? Any Nahara? Any Mak? Any Ognachic? I figure, especially in the latter case, having an uncommon host makes the Visser special in a way--Esplin played that up a lot in the series. And Edriss was obviously a being fan of humans, as we've seen.
I don't know. Thoughts?
1) Visser One: Human
2) Visser Two: Human
3) Visser Three/One: Andalite
4) Visser Four: Human, but previous host is unknown--probably Hork-Bajir or Leeran