Not a ton to say about the selection of units here. This is the only reasonable configuration to keep Mando and the Armorer paired like that.
As for playing, therein lies the fun. I've had some success just piling on Mando, Bo-katan, Paz, and the two supporting units all in a big huddle-pile where they can benefit from Bo-katan's innate, proc Paz's first reactive, and all their 'Mandalorians are Stronger Together' abilities. The Armorer is the interesting bit and she actually does a good job running out and isolating a key target. Bonus points if they've got bad melee stats (cough, cough, inferno squad).
The strength of this whole thing is the Armorer's identity; you just can't trade evenly into this team, at least with attacks. The Bo-katan everybody-gets-steadfast huddle pile can just move freely and grind out positional advantages. If you manage to force your opponent into some trades that get their force costs up (Armorer gaming), you can just build up the advantage and suffocate them out.
