Hey there welcome aboard!

I've kept ACFs with medium-sized worm-like loaches (Okay fine it was weather loaches), swordtails and a couple small angelfishes for years without any problems. You'll even see that the frogs enjoy the slimy presence of the loaches while resting and is fun to watch during feeding time. (Note that the frog may seem to 'eat' the fishes during feeding time in which case they realize it isn't the food they were after) no harm was done and some of my swordtails even thrived from fry to adulthood without gettin eaten