Well, counter shafts can be tricky. You would need to have a set of gears meshed together to reverse the rotation. Between bearings, gears, lubrication requirements, it just doesn't pan out. Cheaper to mount conventionally and keep things a simple as possible.
Johnny, here is a link to a site with all the specs for the Honda trikes-
Enjoy
Also, if you like, I have a honda repair manual for the 200s, I can email you a copy.