It's not about my preference xP It's about what you think might be a more beneficial presentation to you. If they're together, it avoids cluttering your gallery with old work, and lets people view them all in a bit more context, since they're a set. Even with newly made work, people often group related sprites. If you would prefer to present these four all separately for any reason, there's no problem with that at all, it's just a matter of how you want them to be seen.
As for the critique I have: you have a recurring problem on these of using transitional colours in a pixel-thick line, and that line then creates banding with the shadows it's meant to buffer/soften. Banding has the opposite effect of softening, it makes a more jagged, fat-pixelled look. In this one and the Anthony sprite, you can see the problem on the leg on the right, on the Tony and Andrew sprites, you can see it in the middle of their shirts. In all of these cases, it could be quickly fixed by just removing that colour because it doesn't contribute anything of use, or you could take a little extra time to either widen that area or reduce it to just AA (either would break up the banding), so that it does have the effect of smoothing the transition.
Some of the highlights also band with their neighbouring outlines/colour boundaries, but those issues are much less noticeable to me than the above.
I can put them together as one image if you'd prefer, that doesn't bother me. It was just how I had them saved initially. And I am always open to critique, even if they are old. I may end up being aware of the problem that is being brought up, but I don't mind an objective eye even still. :)
I think since these are old, they might've been better off being uploaded as a single image rather than separately.
Also, since these are old, I assume you're not interested in critique on them?
Ah yes! I see what you are saying. I understand AA a lot more than I did then- so I think that would be the route I would go, I also staircased a lot of lines improperly and they look jagged and choppy, and I feel I was dither happy on all of these ._. - That was really great feedback thanks so much!