Not sure what they are, but surely shouldn't need water everyday. The soil looks heavy and not much drainage.
They are probably rotting away. Check the roots, if brown and mushy. Roots should be firm and almost white.
Whatever changes you make do one thing at a time and give them time to respond. Thats the only way you know what works.
You simply can't expect them to rebound daily after abuse or lack of care. HD is known for drowning or drought. Probably already rotting when you brought them home.

I'm pretty sure the last one is a ming aralia, although I'm not familiar with raising it theirs a bunch of information online just do a google search =)

I thought I'd tried to post an answer to this, that I'd tried to look but the pix were too small & distant for me to tell.

I do agree the last pix seems to be a Ming Aralia, aka Polyscias, which I don't believe wants direct light. Prefers bright indirect light, will benefit from a pebble tray.