So, in my never ending quest to make expose viable, I was brainstorming some ideas around Youngster. After all, the main reason it doesn't work well is that you can't take a second action because no PTL, but if he's carrying expose, then you could have everyone else carry PTL. Which lead me to the following build:
Youngster w/ Expose + Shield Upgrade
Black w/ PTL
Black w/ PTL
Black w/ PTL
Howlrunner w/ PTL + Shield Upgrade
You're still throwing 14 dice, which is the same as the standard 7 die swarm, but now it's over 5 attacks instead of 7, increasing their effectiveness. You've raised your PS to 4, so you shoot before all of the annoying TLTs these days and other swarms. And you have 2 main targets in Youngster and Howl, making it difficult to decide who to attack. The one drawback is that you have stress, which limits your movement, but if done correctly, you can utilize the stress on the first two turns to have a 3 dice attack with focus and a reroll (average of 2.68 booms btw), and then selectively use it in the future to stay alive via F+E, or a barrel roll + Focus and the like. The shield upgrades could also be swapped out for 9 points of upgrades, which could change two of the blacks to Scourge and Mauler (and leaving a HU on Howl), giving you even more dice to roll.
And as a question - When Youngster says "TIE Fighters," I'm assuming that is limited to the TIE/ln, and cannot be used on the TIE/in or TIE/sa or TIE/fo etc. right?

