I think we should have a discussion for each hero and as I'm currently playing Fenn in a campaign I'll begin the one for him.

What is his strengths?

What is his weaknesses?

What are some good builds? What should he focus on?

From the get go he has easy access to blast making him good at taking out stormtroopers. He can focus on this and upgrade it to do extra damage/stun but he can also be build quite tanky with adrenalin rush and take cover. Weapon Expert and Superior Positioning would also allow him to deal some good ranged damage and with Tactical Movement he can be as fast as Jyn.

My plan was to first take Tactical Movement as extra movement is always useful, then I plan to get trench fighter (with spread barrel) and adrenalin rush to be able to deal some good close quarter damage regardless of weapon.

Later I would take either rebel elite or suppressive fighter to take better advantage on Havoc Shot.

How are you playing the Veteran Fighter ?

I have not played him, but I'm planning to in our next campaign. I think I will start with Tactical Movement to allow himself or another hero a few extra movement point, and then save up for Trench Fighter. Depending on how much XP we're earning I'd probably go for Superior Positioning next, and use him as a mid-range, mobile fighter. Move+Focus+2 extra damage is quite nice, along with his blast ability should make for a good guerrilla fighter.

I can tell you that the person playing Fenn against me went for Tactical Maneuvering and then Take Cover and then Rebel Elite. The Tactical gave him utility, the others made him a beast to take down.

Adrenaline rush with the tier 1 survival gear, tactical maneuvering, and take cover. I played Fenn like this in a campaign and my imperial friend hated it. He then played Fenn in the campaign I'm running.

I wish I never showed him this.