Would you consider my Zebra Danios to active for certain fish?

I have a 20 gallon aquarium at the moment with 3 zebra danios and 2 longfin danios. I have read repeatedly throughout the internet that zebra danios are to active for some fish. But mine don't seem like the constant dart-y swimmers some make them out to be. They swim at a moderate pace and sometimes get speedy when playing with each other. They have also been in a tank with cory cats before, and they payed the cory cats no mind. So, I was wondering, could my danios coexist with some timid and/or slower moving fish? Or is it just to risky?