I used the T-21 once or twice in a mix with Shoretroopers.
The units had targeting scopes, the captain and offensive push for 94 points.
That way the unit is pretty much guaranteed to have an aim, sometimes even 2. 13 to 17 white dice with critical 2 are actually pretty decent. It usually results in 3 to 5 critical hits. The output is still worse than shoretroopers, but they do have some advantages that make them a good addition to a gunline:
- The critical hits make them more flexible against a lot of targets like vehicles, Tauntauns in cover or units with guardian.
- They can deal with losses better, because their output is more backloaded. A bigger part of it is concentrated in the heavy weapon and the aim tokens.
- Even with all the extras, they are still cheaper than shoretroopers.