I've flown the Decimator once since purchase and really messed up my game with the list build.

If I decide I don't want to take a co-ordinating shuttle alongside RAC, will Rexler do?

Rear Admiral Chiraneau

w/ Dauntless, Trick Shot, Fifth Brother (107)

Rexler Brath

w/ Juke (88)

Total 195

As long as he doesn't hit an obstacle, RAC takes the reinforce to slow down the incoming damage. This then gives him the ability to turn 1 focus into a crit. Fifth brother can then turn another focus into a crit - so as long as the defender is in the reinforced arc, RAC should be fairly consistent in pushing through hits/crits, especially with the extra dice through rocks or at range 1.

Be aggressive as possible with Rexler while keeping him for the endgame, and is there enough here to compete?

Minister Tau and a hull upgrade would be better on RAC I think. Tgst frees up points for collision Detector on Rexler or more toys in RAC. It's a fun list but it's only 2 ships and will struggle against bug hitters.

I’ve just flown the two on Vassal first time. I think Tau is a must but I like Adv Sens on Rex with Juke.

With the remaining I’m thinking Hotshot Gunner on RAC to strip tokens for the Juke shot from Rexlar?

New Squadron

(84) Rexler Brath
(8) Advanced Sensors
(4) Juke
Points 96

(88) Rear Admiral Chiraneau
(7) Minister Tua
(7) Hotshot Gunner
Points 102

Total points: 198