I think I would use snowtrooper and deathtrooper. Remove stormtrooper. And what’s this about troopers not having enough firepower? Mine easily do 8 mil in the Sith raid, and usually considerably more. It’s not heroic, but still, they’re doing more than any G12 fully zetad resistance teams in my guild. My best was a little over 12 mil.
I love Gar Saxon, but I think you’d be better off with a Thrawn or veers lead, and use them in p3. Maybe work in a zVisas. She adds a lot to any squad in p1 and 3.