Not really knowing all of Cassian's kit, this is my speculative 800 point army including him, thematically, with Jyn + Pathfinders, etc. Of course, we don't know anything about K2-SO, which is likely to amend this list further. But, this is my starting point.

796/800

Jyn Erso (110 + 16 = 126)
--Duck and Cover (4), Emergency Stims (12), A-180 Rifle Config (0)

Cassian Andor (90 + 20 = 110)
--Hunter (6), Duck and Cover (4), A200-CFE Sniper Config (10)

Rebel Veterans (48 + 45 = 93)
--CM-O93 Trooper (26), Rebel Officer Upgrade (19)

Mark II Medium Blaster Trooper (38 + 5 = 43)
--Linked Targeting Array (5)

Rebel Troopers (40 + 22 = 62)
--Z-6 Trooper (22)

Rebel Troopers (40 + 22 = 62)
--Z-6 Trooper (22)

Rebel Troopers (40 + 22 = 62)
--Z-6 Trooper (22)

Rebel Pathfinders (68 + 26 = 94)
--Pao (22), Offensive Push (4), A-300 Long Range Config (0)

Rebel Pathfinders (68 + 4 = 72)
--Duck and Cover (4), A-300 Long Range Config (0)

Rebel Pathfinders (68 + 4 = 72)
--Duck and Cover (4), A-300 Long Range Config (0)

Commands:
Rebellious (1), Crack Shot (1), Trust Goes Both Ways (2), Push (2), Complete the Mission (3), Assault (3), Standing Orders (4)

Some things for Cassian. Offensive push, recon intel, leia and r2. If just going for the Rouge one theme, then offensive push and recon for sure. You need to get the tactical 2 so you can pierce crits through. Free moves are really good for him because it bypasses cumbersome

25 minutes ago, Cleto0 said:

Some things for Cassian. Offensive push, recon intel, leia and r2. If just going for the Rouge one theme, then offensive push and recon for sure. You need to get the tactical 2 so you can pierce crits through. Free moves are really good for him because it bypasses cumbersome

Oh yeah I can absolutely benefit from adding those units, but I was going for just a Rogue One themed force lol I didn't like the idea of Hunter on Cassian, anyway, and Offensive Push is nice, even when not using the sniper rifle.