can I add shrimp/goby pair ?

[yahutch]

I have an existing watchman goby / candy pistol pair that I would like to add to my 240g display , but I have fish in there that will not allow me to keep pepp/cleaner shrimp . Would the pistol have a better chance at survival since it is paired w/ the goby and it is a burrowing shrimp . also , if I add them would they be out more or less w/ the other fish around ? They are currently in a cube by themselves and rarely come out now . I have been working alot and would really like to downsize my addiction if possible , but will keep the cube running if the odds are against them . Would you risk it ? and if so , how would you go about adding them , socially acclimate in a clear container or dump them in after lights out when no one is looking ? thanks

current stocklist in the 240g
regal angel
one spot rabbit
copperband butterfly
kole tang
coral bueaty angel
flame angel
pair of osc. clowns
diamond goby
group of 8 lyretail anthias
group of 4 blue/green chromis

and I would like to add as my 2 last fish a pair of blue throat triggers

 

[yahutch]

forgot to add the shrimp killing radiant wrasse to the current stock list