How old are they?
If the are still juvi colors --- I would put them in a smaller QT(s)

Are they catching/finding their food really well?
Same - smaller is better if they are really small---
I do QT is good in stages...for grow out.
Smaller QT so they can feed more easily? ( observe them for a while)

Are they from the same parents ? or are they siblings
If yes -- I would leave them together
If not I would separate for QT
You could call and find out ?

Were they shipped in separate containers?
If they were shipped together - in the same containers --- I would leave them together.