Seems like a single template with 2 tracks would work great.  Set one up for LEFT, the other for RIGHT.  If you only need one of them, it's super easy to delete the track using the input you don't need.
 
Based on total and average clicks counts, that's the way I would go 

BobF
Seems like a single template with 2 tracks would work great.  Set one up for LEFT, the other for RIGHT.  If you only need one of them, it's super easy to delete the track using the input you don't need.
 
Based on total and average clicks counts, that's the way I would go 

why would I want RIGHT if the mic never sends signal over it?

In cases where you're using both LEFT (1) and RIGHT (2) at the same time, or you're using RIGHT (2) instead of LEFT (1).  If you're only ever going to plug the mic into LEFT (1), then a single track template will do nicely.
 
The UR22 has 2 MONO inputs, 1 & 2, which used together make a single stereo channel.  You can plug your mic into 1 or 2, or two mics at the same time.  When Sonar shows you these inputs, it shows them as LEFT-1, RIGHT-1 or STEREO-1, which can be confusing.  When you choose STEREO-1, left will be your hardware channel 1 and right will be your hardware channel 2.
 
When Sonar shows you LEFT-1, it is referring to item (2) below.
When Sonar shows you RIGHT-1, it is referring to item (4) below.
When Sonar shows you STEREO-1, it is referring to both (2) & (4) below.

 
Sorry if I'm making this worse or telling you something you already know ... I'll be happy to clarify more if I can.