There can only be one active Behaviour at a time - much like there can 
only be one application having "focus" in a common desktop OS.

You can, however, assign different actions to the buttons of each 
individual Wii Remote. Remote Buddy manages button mappings seperately 
for each Wii Remote.

So the solution is: 
1) package up all of your actions into one Behaviour, compile and 
install it 
2) connect all the Wii Remotes you want to use to Remote Buddy 
3) go to RB > Prefs > Mapping > "Your Behaviour" and assign the 
actions to the buttons of the remotes.

Best regards, 
Felix Schwarz