Yet you treat every helicopter as a completely different "Type"....which sets you up for that situation.
At least in the FAA system....anything 12,500 pounds or less is considered the same "Type".
I use the adage..."A helicopter is a helicopter is a helicopter!".
They all have far more in common than they do differences when you really get down to the basics.
It is the differences that matter when it comes to conversions/transitions.
Why not focus on those?