Two Basslets in a small tank?

[Benny Cavalino]

Hello folks, just a quick question. I am about to start up a 20 gallon aio tank. Since its a small tank I'll probably have only three maybe four fish in total.
Might it be possible to introduce a chalk bass and a royal grammar at the same time as my first two fish? They are not exact but they are still basslets. Thank you

 

[Esage]

Good question. I've been wanting to add a chalk bass but I currently have a swissguard in the tank