i have at one stage kept 10 kribensis (male and female, non breeding) in a tank with clown loaches, guppies, bristlenoses, blue ram, fire eel, and i never saw any aggression coming from the kribs. aside from the baby guppies disappearing at a very 'population control' rate. and anyway i more suspected my fire eel to be eating the baby guppies!
kribs are a great community fish! great fish all round - they are beautiful fish!