guess very much depends on fish
i place my flame wrasse in sump compartment, 1 x 1.5 x 1 feet
stay 1 corner, not feeding
decide to move to DT after a day, happily swimming and feeding
after that experience, i place all my fish in DT after acclimatize
i notice 3 main reason why fish fight
1) same family, eg dwarf angels, clowns
2) similar appearance, eg yellow tang vs copperband butterfly
3) aggresive in natural, eg peppermint hogfish, maroon clown