I do not understand the term dither fish; however if oyu are asking
are blood parrots and WCMM's + Danios compatable then the answer is yes
as long as the WCMM's and Danios are adults.
Cichlids tend to be shy and therefore need to see other fish swimming around to be certain it's safe. these fish are called dither fish.
They should work, though they might either scare the cichlid by there movement (probably not) or tehy might nip the cihclid if it's alone. I'd suggest livebearers or other slow fish, but danios should be ok...