the first 2 are definitely voltage controlled amplifiers!- so they can double as input modules - and potentially add some grit if needed - not sure about the malekko
most vcas, whilst technically amplifiers, have a max gain of 1 - so really constitute a different class of module - voltage controlled attenuators - which makes things as confusing as before as the TLA is still VCA!
I've got the older mutable veils - and I like that - no need to upgrade to the newer version, which I expect would be just as good if not better (and a little smaller) - so I recommend veils over the other 2 - but at the end of the day it's up to you: get the one you can find, at the price you want to pay, with the features you want!
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities